I use B+W MRC by default, and Hoya Pro-1 Digital for the wide angle lenses, since they are thinner and make for less chance of vignetting. If you use a UV for protection, thinner is more important when you stack a C-POL with a UV.
Canon designs their lenses to allow for one filter of normal thickness. Using EF lenses on a cropped sensor camera lets you stack more filters before vignetting becomes an issue, so you shouldn't have much to worry about with your current kit.
Hoyas are hard to clean, but I have found ROR (Residual Oil Remover) to work very well. If you go after the Hoyas, get some ROR as well. It is hard to find, but B&H carries it.
Hope this helps.
Have Fun,