Sometimes I get "happy fingers", too!
I think that running shoes are specific for running, in terms of their composition and size.
Here is the "definitive guide" about shoe selection with respect to your questions -- just follow the link
http://www.runnersworld.com/article/...4615-0,00.html
It might help you decide about what shoe will fit your needs the best.
Also, check out the shoe thread at the top of this forum page -- it has gots tons of great info!
Kira