I am running power from my 200A box to a hot tub, It will be a 100' underground run to a disconnect switch, then to the hot tub. I will power it from a 60A breaker on my main. Should I use 6/3 UF and run a separate line for 2 sets of GFCI outlets, use 4/3 and a larger feeder, or what?

Depends on the power requirements of the hot tub and how you plan to wire the outlets. What was your plan? Is the disconnect set up for more than 1 circuit? You can't pull a 3 conductor and get 120VAC along with the 240. NEC 680.40 outlines what needs to be done. Your installation manual should also detail what to do.

hmm...
Making something work is easy, making it safe as well takes planning. There were a few swimming pool accidents and fatalities this year so giving you a simple answer would be inappropriate.
As recommended above there are requirements in the National Electrical Code along with the manufacture's requirements that must be observed. Good grounding and bonding installations are critical to prevent another swimming pool incident.
Sometimes hiring a professional is the least costly way to go...

First and foremost, you cannot run UF outside to feed a hot tub. You must use insulated conductors (even the ground) in conduit.