There are lots of good guitar shops nationwide such as Music-ground in Leeds, who stock a fantastic range of good quality instruments. The problem is finding a number of shops in the same area so that you have some direct comparison. Coming from the North East, I can find a handful of good outlets but, if I want to try one guitar against another, I'm usually better off making the trip to London, perhaps making a weekend of it, and head to Denmark St.,where, in the space of a couple of hundred yards, you can pick up and play all the best makes side by side.
Another good shop in London is the Accoustic and Bass centre in Wapping High St. The last time I visited they had a whole wall full of Collings guitars amongst dozens of other beauties, all nicely set up and available, without fuss, to try.
If you want to try them through an amp. there's a room to use and you're not bugged by salesmen standing over you.
The staff at these busy shops ought to know what they're talking about and in my experience they usually do, so you should be able to ask for help in choosing what's right for you.
I hope you find what you're looking for and I hope finding it is a pleasure.
Good luck,
C-flat