I don't think a guy with a 100k budget should buy a Testa Rossa. One 5 figure repair bill and he would not be to happy. I think the 360 with a MT is his best bet.
360 would be your best bet IMO but finding a good example might mean spending the whole 100K for a MT. You didn't specify if the budget included maintenance, taxes, etc. also be sure to get the factory race exhaust which makes the car 100x more enjoyable.
Hate to say it..but you will be disappointed with a ferrari compared to a Porsche performance wise. The 360 as others have said is your best bet (perhaps your only bet?) at this point in the market. I would hold out until next year and try an get into a 430.
Josh, pull up a chair and keep reading. May take a year or so, but I'm sure you will find a F-car that you "want". Good luck with that.
Thanks everyone for the great suggestions and posts. I really appreciate it all. You are right, I am taking my time in order to find the car. Detroit winters can get pretty brutal, so no rush...The leaves are already starting to fall. Thanks again, and happy motoring to everyone here. Josh
There is a very nice looking 2001 360 spider with 20K miles under $100K for sale right now in the For Sale section. No affiliation to the listing.