My wife and I have been slowly remodeling our out with the linoleum and laminate, in with tile and granite. Part of that has been slowly replacing the fixtures with those of a different finish -- including the shower head and handle. I've found set on amazon that I believe would look nice, but it comes with it's own valve body. I'm not keen on ripping out the wall to replace a functioning existing valve body; can I just use the handle and facia off of the new handle, while keeping the body from the old handle?
It depends on what valve you have. What you're looking for is called a shower trim kit. When homes are built and the plumbing is done the shower valve is installed. Later the customer/homeowner picks out a trim kit which is the plate, handle and shower head. Depending on what valve you have there may be a good selection of trim kits or none at all. There is a bit of savings with the trim kit because you're not paying for a valve.