Very Nice Review of these Cars. I understand loving 6MT, but you seem to be bordering on obsessed lol.
430 is a fantastic car, but so few are 6 speed, so it will be very tough for you to find one.
the 430 scuderia doesnt come in a 6 speed, and neither does the 458. So you may not be a ferrari fan boy if a 6 speed is a necessity. I'd say drive a MY10+ GT3/GT3RS.