There's a really nice high-end block for sale here:
CUPLEX XT DI CPU water block $150 - RedFlagDeals.com Forums, if you're interested in spending some good dough. The price is a little inflated, IMO, as the seller seems to be taking advantage of the fact that the block is almost impossible to get in North America, so you might be able to work him down a bit. But it's a high-end block, as I said, so you'll be paying more than you would for D-Tek/Swiftech/etc.