Toilets, Sinks, Showers, Tubs and Disposals - Faucet Upgrade Advice - Please Help

I have a 3-valve, washer-type Price Pfister tub and shower system that I would like to upgrade to the ceramic washerless-type. Can I change from a 3-valve to a 2-valve system or even a one-handle shower handle type (with tub spout) very easily without having to rip into my tile?
I have access to the brass valve body/manifold behind the wall and all of the attachments are threaded couplings and nipples - no copper sweat connections.

From what I've seen on the web, the 3-valves are limited in design options and 2-valve and one-valve shower type systems are cheaper.

Thanks for the advice,
Brian

You need to go to a plumbing fixture and supply store to check out the various types of new tub/shower faucets.
They have some new types out now with large chrome or brass estucheon plates that cover the old work from the unit side, and the faucet body can actually be installed from the tub/shower side too (although you don't need to).
Good luck!
Mike