I'm assuming that you have an idea of what interests you and that you are shooting for a PhD or masters by research.
Research your topic of interest on Google Scholar. Read widely to identify who are doing comparable work.
Write a research proposal and send to the professors who are doing and supervising such work. You need to be very passionate about your topic in order to sustain you through 3-5 years of grad school. Of course, what you write your thesis on won't resemble your research proposal. That's just the way it is. You discover so much as you dig deeper and deeper into your chosen area.
I'd use it full-screen with pyGame and experiment with implementing the view part of MVC and alternative user interface (that requires no keyboard nor mouse) think gestures, taps, etc. Direct manipulation has a huge promise when applied on a larger scale. Look at iPhone / iPod Touch and the various Surface systems for inspiration.
I prefer AWS/VPS. That way I have root access to a virtual machine and can pick and choose what I install. Personally I prefer Ubuntu environments, apt-get is so convenient. I do my development on a personal system and upload working code for testing / deployment. From my experience GAE imposes constraints which may turn into issues.
My neck doesn't hurt either, I've been at it for over 20 years. Maybe your ergonomics are wrong.
The bigger issue is that you aren't excited by what you are doing, so ... STOP IT! life's too short to be doing something you hate. I've gone back to university to get a PhD, I'm using my brain heaps and interacting with some very smart people. It's not for everyone, but if you are looking for a mental challenge, even a year long course in something that you are intrigued by might recharge your batteries.
Corporations will only hire drones and you have to prove that you are a drone in order to get hired. By being entrepreneurial you are automatically labeled as an anti-drone, therefore, no job. The only border line exception to this rule is sales. In sales you are expected to be like the hunter's dog, bring in the game and be content with getting cold leftovers the next morning. That's after it was you that jumped into the freezing lake not the hunter.
If your adviser thinks highly enough of your work and potential, then he will make suggestions as to how to make it work. On-going collaboration would have to be the go. You don't actually have to sit at his feet to succeed. If on the other hand he isn't encouraging you, then may be it's a case of hero worship and you need to get on with your own work.
Get some "real world" experience first. I got bummed out doing a Masters many years ago - got distracted by money making ops. So 20 years later I'm back doing a PhD. The topic is more practical and yet breaking some new ground from the academic perspective.
Don't let money dictate your decisions. Seek to optimise your experiences and that goes for life outside of IT & work. The startup option will teach you the most. Just don't count on getting rich. It so spoils the experience.
When you do what you really love, you don't count the money. Your pay-off is from the sense of accomplishment. Doing something for love and wishing that the money follows really depends on who else gains value from what you do. E.g. living in a log cabin in Alaska - minimal payback. Creating, building and selling iPods - huge payback. The difference being not many people are chuffed at you living in a log cabin. Lot of people are very chuffed at having the music they love when they want it and having a cool gadget to play it on.
I too was a SAP consultant! Yeah it sux big time. I saved my money, got a biz started in my spare time and jumped ship when I had a nest egg and the beginnings of a business. I'm not a millionaire ... yet. But Much HAPPIER!
The economy is not looking good right now. So I suggest hanging in there and saving as much as you can. You might even get retrenched and get some severence money to top up your savings.
Of course, if you're happy with you big spender lifestyle, then that the Faustian Deal you've made.
I'm using two HP/Compaq Presarios, both with Ubuntu v8.10 and Mac4Lin. I was going to buy a Mac, but considering the price differential the Compaq's are a better deal. Ubuntu upgrades also come at the right price.
Research your topic of interest on Google Scholar. Read widely to identify who are doing comparable work.
Write a research proposal and send to the professors who are doing and supervising such work. You need to be very passionate about your topic in order to sustain you through 3-5 years of grad school. Of course, what you write your thesis on won't resemble your research proposal. That's just the way it is. You discover so much as you dig deeper and deeper into your chosen area.