Which would you choose?
a.) Depends, if you don't have to travel at all and live in a place where the weather is usually warm, a bike. Otherwise the mustang.
b.) A Harley (I love them all) or a Ninja. As for the mustang, I would get any GT that is hardtop. Convertibles have way too many problems, and a Conv mustang, you would be throwing away your money. Also, if you don't get a GT the mustang is completely useless. I would save and get it brand new, that way you will have the dealership to back you up when you get some technical/mechanical problems.
c.) You can find any image you want on Google. And if you want to see the interior/engine of the mustang use ebay motors, you can pretty much find any car you want/like there.