I hate to say this but if I had all 3 infront of me and I had my choice. I would go with the M3. They are one sweet machine. I would of course go with a coupe though so I could track it.
The Saleen paint work is a crap shoot. some good, some bad. I have had 2 my '99-0037 S351 and my wifes '00-0864 S281.
I have had no problems with the S281, The 351 was mess from day 1. Get the 355 gears, it really wakes it up. If your looking for a daily driver.... get the bimmer