There are quite a few wheels that come with a clutch these days. Thomas, ECCI, Ball Racing Development, Frex, and Redline to name just a few.
The clutch is often an option as some games do not suport a clutch. No need to purchase what you won't be using.
I'm not aware of any wheels that come with a gated shifter. This is strictly an add on product. Most of the better sims allow the use of two controllers. #1 is the wheel and pedals and #2 is a gated shifter.
AFAIK there are a limited number of manufacturers of gated shifters. Thomas has just released theirs. Act-Labs used to make one with different plates for the shift patterns. I think they can still be found on Ebay from time to time. Frex has recently entered the shifter market too.
A site with lotsa good info on sim racing is
www.racesimcentral.com