I'll have to find the paperwork for my bed liner but I used the place the dealership would have used and paid them directly (without the dealer markup).
Spillar Hitches is well known although I don't know their prices. I used Pickup Heaven a while back but only bought the steps from them.
Installing them yourself is pretty easy, especially with air tools.
find an AOL CD, install it, click the internet button, go to google, search for what you want and buy it there.
Shops don't stock that stuff anymore, its cheaper to order online and pay shipping vs tax, and you get what you want instead of whatever cheap smittybilt or steel horse crap the outfitter carries.
Pickupspecialties.com is based in spring. I worked there for like 3months till I got a job offer else where. They carry some pretty good stuff. Customer service is sub par but their stuff is good.
Texas Hitch & Truck Center off of 183 has treated me pretty well. Not sure if they do bedliners, but they have pretty good prices on tool boxes and bumpers.