need advice on buying an F355

I'm looking to buy my first ferrari (I have focused in on buying a 1995 to 1999 F355 in the $70-$80 thousand range). I've seen and driven 2 cars in this range. Of course, I've fallen in love with both of them. In regards to the 355 model range, do you think it is better to get an older car (ie.: 1995-96) with lower miles (ie.: 8000 miles), or a later model car (ie.: 1997-1999) with higher miles 25-35 thousand range)? I've read that issues with 95-96 cars include valve-guides that wear out fast and Cats that go bad in these early model 355's. Is this a true concern? I have always been partial to a GTB (coupe) versus a GTS or spyder, and gated manuel versus F1 paddle shifts (although I've never driven a ferrari F1 transmission). I've been looking for cars in California, and it seems most cars I've seen advertised are Spyders and F1 shifters, thus coupe and manual shifting seems to be rarer in advertised cars in Ca. In the market, is there more of a premium for a spyder, or for the formula 1 shifting, despite these options appearing to be more common? Also, I've heard different words of advice regarding service of these cars from magazines and dealers. How many miles or years is the correct major service intervals for these cars? What is the yearly expected normal maintenance costs of owning a 355?

I appreciate any advice any of you guys have regarding this issue.

Hoping to live the dream very soon!