I could never get used to anything but 9's (Ernie Ball Super Slinky) - they allow me to play faster, bend more easily and there is less string noise off the lower end when moving positions. String gauge is totally individual, whatever you start out on is more likely to be the way you go forward.
I have used hybrid sets before with good effect on my 7 string guitars - from the 9 gauge pack for the top 4 strings and the heavier set for the lower three. This helps you to get the heavier tone for rhythm and still be able to glide around easily for lead. Something worth considering.