The ones on eBay sold by user "macilwu" are very high quality- he built a few sumps for people in WNY (myself included) and the craftsmanship is top notch. If you decide to go that route, submit an offer and let him know that I referred you.
How big are you looking to go? A cheap 20 long (30x12x12) or 30 Breeder (36x18x12") would both work well for a smaller setup. Getting a glass tank custom made isn't cheap, trust me! :spin2: