injection to carb?

Hi guys im running a 2l 8v inj with kent cam and some head work done ive been looking at going down the carb route. Ive found a set of Webber 40s with manifold for ?350 but im not sure if 40s would be enough or do i go for 45s just after a little feedback before i get to involved and are they more hassle then there worth :dontknow:
                   Thanks Mike.

Would you remove double glazing and install single glazing if you read on the internet that it was better?

Paul have you run carbs?