Welcome to the scene Beast96GT, As for your queries...
1. Yes, 3.1 is possible and is a top upgrade you can do to any Amiga.
2. We would most likely have to see pics of the cards before we can tell you what they are (or atleast a good discription).
3. Wouldnt know as im not in the US.
4: Look out for the battery on the motherboard, they are prone to leaking very badly making both mess and damage. Also PSU's have been known to blow but other then that you should be ok.
