I have some comments which may be useful. I'm a computer science undergrad student in Australia, who also studies Indonesian and has visited Indonesia twice before. I, too, have looked out the window of a bus at the beautiful landscape of Java and wondered if I could work there on a healthy US dollar income. My experiences are more to do with living in Indonesia itself than getting work, so they may or may not be useful.
There are advantages and disadvantages to moving a business to Indonesia. You are right that with a US dollar income you could easily afford to live very well in Indonesia. Moreover, I believe you could earn a living from overseas.
My experience in Indonesia is that westerners are warmly received and people will be happy to become friends with you (that said, there are people who "befriend" you just for money, and there are also a handful of militant extremist Islamic groups... these guys did not cause a problem for us any time we were there, most recently July, but things have changed and I would not advise travelling to Indonesia until things have cooled off somewhat.) Shortly after America started bombing Afghanistan, one of these groups went to a major US hotel and demanded that the Americans be brought out so they could be trucked to the airport and thrown out of the country. In the end I don't think anyone came out though, and the group left without causing a riot. I'd recommend saying you were Australian (my tutor got around Indonesia during the East Timor crisis and avoided the possiblity of trouble by telling everyone he was a Yank!)
As to getting a job, you'll have to rely on others with respect to contract work, but from my bedroom in Australia I create the partial illusion of a small shareware company which sells educational software to individuals and schools. People tend to assume I'm in the US without asking.
Unfortunately, living where you want to, in the times we are in, has it's disadvantages.
Do you speak Indonesian? I have never been to Bukit Lawang, but during my time in south Sumatra barely anyone spoke English to any great degree. This didn't bother us, and if it doesn't bother you then you'll be fine.
Are you content with being a celebrity? Again, Bukit Lawang may have more bule (Indonesian slight-derogatory slang for a westerner) around than South Sumatra, but being white there made you both an assumed rich guy and a novelty. This can be great fun, but it can wear off. After 10 days in the Bandar Lampung area we were glad to get back to Jakarta where you weren't an automatic novelty. Walking out of a department store in Lampung, my friend and I turned around to find at least eight female clerks, standing in a line through the middle of the store, laughing at us! (Granted we were their age, both over six foot two and white!)
Also, being assumed rich can have difficulties when you are relying on expensive gear (computer, modem, etc). This may not matter if you can settle in a little town and get to know everyone. It may not matter anywhere, but remember that you are instantly worth many times what ordinary Indonesians take home from months or years of work.
IT Infrastructure. OK, so you've got a modem. Do you have a phone line which will carry the signal? Do you have an ISP within local call range? If you get a satellite dish, will it work/be affordable/not get you arrested as a "spy" by the local polisi seeking "fines" from a decadent westerner. Not a problem in Jakarta or any major city, major problem in the middle of nowhere. Even here in Oz many outback towns can't get a modem running at more than 4800-9600bps.
Do you suffer culture shock? As said above, being one of the only Westerners in a foreign culture can get to you. It may not get to you specifically (I have seen people not mind, people become homesick, and people freak out and panic because a bellboy brought them towels!!), and you will no doubt make many good friends as we did, but before long you may regret it. If you go most anywhere in Java or any major city, this will not be anything like as much of an issue as in Sumatra.
The advice you've had to make business opportunities for local merchants is a good one, but I fear it is more suited to a place like Jakarta than one like Bukit Lawang. I may be wrong, of course. The advice to set up a school could be very valid if you had some capital and a few old computers to export. But then you'd be making Rupiah, not USD...
My advice, if you haven't done this before, is to travel to the area alone (or with the person/people you're going with.) Go to the area you want to live in, and wander around talking to people. Ask if someone will put you up for the night (they will!) and spend a day or two living there. Spy the non-Western bathroom arrangements, the discount voltage-regulation gear on the TV and other electronics, and make sure you can handle the heat without retreating to Aircon. Talk to the families you're staying with about moving, about getting a house and about their thoughts. Depending on who you're staying with and the income in that area, they may even have their own computer (one of my strangest experiences in Indonesia was fixing the VCD player on a friend's copy of Windows in Bogor.) If they are anything like the people I know in Bekasi, Bogor & Bandar Lampung, they will offer you all the support you could accept.
Go to the local Wartel (basically a small business offering public telephone service and occasionally net access) and talk about getting a phone line, net access, etc. Maybe you've done all this already, but I'd want to be sure I could hack it before I upped and moved.
Finally, good luck. I would love to know if you succeed or not, as I have daydreamed about it myself.