Cat 5(e) is fine. It's pretty much standard. I've yet to see many real uses for cat 6. Run it if you want, but there's not going to be much of an advantage.
Run 5 RG6 from the dish location to the wiring area. Why 5? Because DirecTV uses 4. Even if you're only planning on Dish, you may want it for later. That leaves one extra for OTA or use as a spare.
I'd coil a few extra feet on each cable and then throw the ends in a waterproof j-box if you're not going to use it right away. If you're hooking up a dish right away, it's not really necessary.
Also don't forget to at least leave access to and coil the cable where the ground block will be so you can cut and terminate it later.
Run all cat 5 and RG6 at 90 degree angles to power cables. If they are running parallel, leave 12+ inches spacing between them.