You can't really go wrong with any of the miter saws that Bosch, DeWalt, Hitachi or Makita make. The new Milwaukees are supposed to be good too. If money were no object, people have nothing but rave reviews for the Festool Kapex but to me, $1300 is nuts to spend on a saw.
Blade size and sliding / non-sliding is going to depend on what you plan to do with it. Go to a real tool store that has all of them lined up and play with each one that you are considering and narrow them down based on whatever criteria you want - comfort, dust collection, lasers, digital readouts, etc. Once you get a hands on feel for the tools, compare specs, read reviews online, visit woodworking forums, and see if they have the capacity to do what you want / need to do. Then after you narrow things down again, go back to the store and really study the 2 or 3 that you are really serious about. See if the store will let you demo those units in the store so you can get a real feel for them.
I'd be more concerned with getting the right blade(s) than being able to share it with your tablesaw. You aren't going to use a fine tooth finish blade to rip 2xs and the coarse tooth blade from the TS shouldn't really be used for finish trim and moldings.
It's not a simple purchase to make. Take your time. You don't want buyer's remorse right after you get the saw home.
