You don't need a Canadian company - you can do the Canadian side yourself. (permits/brokerage/receiving) You will need someone in the UK to take care of exporting/brokerage etc. There is PDQ, they are expensive...
If you are interested, I can also send you contact info for a european dealer out of Iceland who has assisted with guns from europe - I have sent a few people from here his way with good results (not completely without hiccups)
I _can_ refer you to a Canadian company if you really want to, but like I said it's really not necessary.