Photographers in Mayfield, United Kingdom

http://www.lensesforhire.co.uk/

Any full frame body, since you're a canon user the 5D Mark III is the go to body, but any other Canon full frames should do the job (6D? I'm a nikon guy so i'm not sure about canons bodies). When I'm shooting a wedding I have 3 go to prime lenses 50 mm 1.4, 35 mm 1.8, 85 mm 1.8 and a 70-200 mm 2.8

http://calumetrental.co.uk/ are another option. How fast can you learn to use a new camera and lens though? All of canon's better cameras (5D 6D 7D) have a different control layout. If you move up to full frame (5DII 5DIII 6D) you are going to be getting a much shallower depth of field than you are used to. The traditional wedding lenses (50 f1.2, 85 f1.2 70-200 f2.8) are going to have a far shallower depth of field when wide open than you are used to. What lenses are you using at the moment?

I have shot quite a few weddings (30+) and I absolutely love doing it. Its hard work but rewarding. Over the last few years I have shot with 550d, then a 7d then 5dmk2 then 6d. I prefer the image quality of the 6d (10,000 iso usable images? Yes please) however they took the focus point joystick off it. If I was in your position (and tbh i have been in the past) I would seriously consider shooting with your 550d as you (hopefully) know it inside and out then spend money hiring good glass (canon 24-70 and 70-200 2.8 and a fast prime). I had the 550d as a backup until last year. Its capable of amazing images though noisy in very dark situations. You don't want to be missing shots as the controls are different. Yes full frame has its advantages but glass can make a bigger difference. Also if you can get your head around off camera lighting you can really up your game. Saying all that, I have just sold most of my canon gear and switched to the Fuji x. I will still have a 6d in my bag just in case... Edit. To actually answer your question yes lenses for hire are amazing. Delivery is a bit pricy though (£32 pickup and return fee)

I used http://www.hireacamera.com/ to hire a sigma 150-500 before and they were fine, it arrived in a proper hard case by courier etc.