Look at the website www.2filter.com
as they have great prices. Hoya, Heliopan, and B&W are generally regarded as they best and if you buy their higher end stuff you will have good filters. Singh Ray makes awesome ND and grad ND filters and you can order directly from their site. Read the recent Vari-N-Duo thread. Very nice ND and polarizer combo. Pricey, but nice. For cpl, I have been most happy with my Hoya Pro1D and Hoya HD. Very nice stuff. The issue you will have is the larger size needed for the 16-35. That is going to cost you some dough. Read the sticky about uv filters either here or on the lens forum. Tons of great info there about the pros/cons of using them. If you use uv filters, get good ones. I use Hoya Pro1D and HD and can't tell I have lost any IQ. But again, this is worth reading up on. I put a thread on here with a poll last month and the majority use them, but it was perhaps a 60/40 split. Bottom line, cheap filters of any kind are not worth buying. You get what you pay for when it comes to filters. I would start out with a high quality circular polarizer then decide on the other stuff later. The cpl is worth its weight in gold if you enjoy landscapes. The others can wait till you decide exactly what you need. For cpl, give thought to if you need a slim model that will help with vignetting. Also take note that many don't have front threads which means you can't use a lens cap. The Hoyas I have both have front threads. Partly why I chose them.
Canon 5D Mark II & 50D with 17-40, 24-105, 100-400, 50 f/1.4, 100 f/2.8 macro, and 1.4TC
FEISOL CT-3442 (ARL) tripod w/ Photo Clam 40-NS ballhead