If you just want to row gears for street use, definitely go for a Mach 1. GT350's are great cars but more suited for track. They will probably require more expensive maintenance as well. Plus it's best to get those voodoos warmed up fully before having fun.
HOD and SpeedSF are both great programs for Novice/Beginners. HOD is a bit more pricey but more in depth. SpeedSF is cheaper and still a great program as you get about five 20 minute sessions with signaled passing. Both great options!