#2 sounds problematic.. Low miles and NOT properly maintained tells me someone would rather sell the car than put money into it.
#1 sounds better, imho, but will reserve judgement untill you look at it and report back. The front bumper cap is from a 996 GT3.. Check to see if there was body damange or why it was replaced. Maybe it is a "track junkie" car
While some say buy the newest, some others say buy the one with "reasonable" miles as these cars don't seem to age well if NOT driven frequently enough.
Let KBB, NADA, Edmunds etc help you get close to a price. Realize that February, in the NE, is NOT selling season for a convertible. A buyer should be willing to deal. Perhaps the "firm" price is because of an outstanding loan that needs repayment?
BTW, Original MSRP means nothing. Just shows how much these cars depreciate. IIRC, there were very few changes between '01 and '02.
RMS - Rear Main Seal. There is no cure. Some cars have failures, others do not. It is a small, cheap seal. The issue is you need to drop the transmission to access it. If not leaking, don't touch it. If leaking, consider how much it leaks and if you want to pay say, $1k to get it replaced. If you have to replace it, consider reviewing condition of the clutch and replacement if needed.