Originally Posted by
MRT2
I was gong to mention that but figured it might confuse OP. But you are right. A bike with a freehub is better, though if you already have an old 7 speed, it probably doesn't make sense to upgrade because of cost.
Reliability and durability. Doesn't want something that will give him a lot of trouble.
Cassette hub is the first thing that I would look for.
#2 would be no twist shifters.