I've got silly wide feet and shoes are a real pain.
First thing I would suggest is get yourself over to one of the Tredz stores, they should have a Specialized BG Footbed Device you stand on which will give you an indication of which types of soles you may need.
It's pretty basic but it works, I've used the one in Cardiff but I've not been to Swansea (I guess they should have one).
As for wedges, if required, I would suggest cleat wedges over insole wedges as with the latter you start to decrease the volume of the shoe which can make things even tighter for your feet.
You may also find that your feet swell when they warm, so doing the shoes up too tight at the start of a ride could also cause you problems.
Best bet is to find a hill and climb it a few times for s simple wedge test, once you're settled into a rhythm try to feel if you're pushing on the pedal with the outside or inside of the foot - If so wedges will probably be needed.
These are just basic tests I've used for myself based on Steve Hoggs info and other stuff out there on the web.
Sidi Mega and Bont Vaypor are good for wide shoes, I hear Lake also do a good model and some Specialized and Northwave shoes come up wide as well.
Check out a fit wizard to see if you need wide shoes;
http://www.bont.com/Cycling/items/support/size.html
