[GuyBFF]

Like kevin said, use a heater core from the auto parts store, probably a '87 chevy chevette, as there nearly identical to the big momma / d-tek. I'd solder on 1/2" barbs, as a little extra flow without any extra heat is always a bargain (also if your real cheap, you could get one from a wrecker, just make sure to clean very well and verify for leaks).

The pump you show looks submersible, which requires you make a resevoir, adds heat to the water, and as I haven't heard of anyone using it, you'll be the guinea pig to see if it just stops working (this happens).

Get a danner Mag-Drive 250 from petsmart or your local retailer. There reliable (usually just get noisy before maintenence, but keep pumping), fairly cheap and if you look back there was a recent thread for $10.00 off your first order at petsmart. Also get one male and one female 1/2" NPT to 1/2" barb fittings. Use some teflon tape, and DON'T overtighten the intake barb (or you'll split the pump). Some people say the Mag-Drive can leak around the head, this is caused be the hoses leveraging and warping the head if there to stiff. Be careful of this, and if you have a problem, you can fix the hoses, or add silicon sealant to the o-ring.

For waterblocks I'd get the new "upgrade" Danger Den Maze 2, it's 42.00, but comes with a 4 corner mount setup, which once you add up the pieces you'll need to mount the other blocks, isn't much different, many also consider this the best waterblock, and it flows very well, so you won't need a stupidly oversized pump, the 250 Danner is probably more than enough for a 1/2" system with a heater core and this block, all very high flow.

Find some good 1/2" ID flexible tubing (Danger Den sells Silicon, but it's pricey). You need to watch the pump intake to make sure it doesn't suck the hose flat if it's to flexible, and make sure not to use anything thats so stiff it leverages the waterblock (holding it on edge, making poor contact). In a pinch home depot has clear vinyl, real cheap, just watch you don't kink, and the pump doesn't vacuum it flat (you can sometimes stop this be placing zip-ties every inch for the first turn before the pump). I'd also use some sort of clamp (either gear clamp or those plastic snap together clamps). Not totally necessary but for the "just in case" factor.

Oh Ya, get a 1/2"x1/2"x1/2" T-Fitting and place on the highest point above the pump outlet (most bubbles will collect in the pump, so when you shut off they will rise to the fill tube). Put a length of hose on it and plug it some how. This will remove bubbles from you system, and perform as a fill hose.

Good Luck