I have Speedplay Zeroes and they are awesome. I had Look pedals before but ended up having some issues with my knees. I switched to Zeroes about 4 years ago and haven't looked back. It took me about a week to get used to the float, there is no tension and your feet feel like you are sliding around but after you get used to it they're great. You can clip in on either side which I like and I have only had about one issue with my knees since switching. I keep the cleats clean and use a dry wax lubricant about once every 1-2 weeks and also wear cleat covers when I'm walking around to extend the life.
As far as wheels are concerned if you're going to race get something you can afford to rebuild/replace. My crit bike has Mavic Ksyrium Elites, they're light and stiff enough. There are some good Neuvation wheels available for cheap and also look into custom wheels from local wheel builders. I had some Easton EA-90 SLX that were decent but not stiff, had some EA-90 Aeros that were stiff but kept popping spokes. Had some heavy Shimano RS-10's that a buddy gave me that I didn't like. Had a set of Mavic Open Pros with high spoke count that were heavy, stiff, and bombproof. There are so many options available, check out
www.roadbikereview.com, there are forums and even a separate forum for wheels and tires. If you do decide to go custom and crash and break a spoke or rim they can rebuild the wheel cheaper than what it would cost to replace the wheel.
I don't think I will ever get another set of tubulars. They're just too much of a pain, the ride sure is sweet and probably the best I've experienced but it wasn't worth my time. If you've never had tubulars they are messy and time consuming, but if you're just going to use them for racing they might not be a bad option. I didn't mind taking the time to stretch the tires and then glue them, it was cleaning the rims that was the PITA. I had a set of Zipp 404 cross wheels that had 32 spokes front and back that were stiff as you know what and they weighed about 1300 grams. I bought them from a Zipp rep, they weren't available for sale to the public. Not only were they stiff, they rode like a dream but I got several flats and got tired of cleaning the rims. If you do end up getting tubulars you should look into Stans sealant, after I started using that I didn't have a single flat. I switched to Zipp 404 Firecrest clinchers just over a year ago and haven't looked back.
I need to get some pics of my new MTB up, I'm back on the trails since jtrain keeps making fun of roadies.