I didn't think there would be a day where the answer to:
"I guess, if you had it all to do over, what would be the best starting point? What has the most "Available" upgrades?"
Would be A1200. Today, you have more 'new-ish' upgrades for the A1200 than just about any big box Amiga. You'll still have some difficulty finding an accelerator, but better chances than working with your A2000.
AGA may be important if you want to play old games like you say. There really are not that many RTG games anyways.
