Just a quick piece of advice...it would be a
cheaper to get a 52 to 58mm step up ring and a new 58mm lens cap for the 50mm 1.8 and use the same polarizing filter on both rather than getting a second filter. That way any filter/hood/etc you buy for one lens can be used for the other in the future as well. I've got a 500D with the kit lens + 50mm 1.8 and did that and have been happy with the setup. Only thing I'd add in there if you don't have one is tripod, which is what I'm currently doing some shopping for.