Danger Den doesn't really promote any discounts in there kits, so I'd just go and purchase what you need seperately without the peltier (TEC).
They are a good idea, but will bring the CPU below room temperature, which will then require protection from condensation.
Unless your prepared I'd skip the part for now.
I'd suggest:
Danger Den Maze 2 with 1/2" fittings-$42 (already has mount built in, so about same price as others once you add mount, arguably cools best)
Pet Smart Danner Mag-Drive 350-$43
For Rads depends what fits well
D-Tek Cooler Core-$43 (newcomer heater core just like Big Momma with 1/2" fittings)
Case Etc Overclock-Watercool Big Momma-$50 (about as good as it gets, costs $5 to get it modified to 1/2" barbs)
BE Cooling Aquacube-$55 (fits 1/2" and cools beter than Danger Den Cube, fits in small cases, 120mm fan mount)
-7' of 1/2" ID Braided PVC hose-$7 (doesn't kink or compress as easy as clear vinyl)
-One Barbed T-Fitting 1/2"x1/2"x1/2"-$1
-One Brass 1/2" Barb to Male 1/2" NPT-$1 (for Mag-Drive)
-One Brass 1/2" Barb to Female 1/2"NPT-$1(for Mag-Drive)
-Ten 1/2" Stainless Hose Clamps-$5 (fit 3/4" OD)
Total $142 - $155 (will cool better than any of the kits and about the price of the cheapest)
Use Arctic Silver II when mounting water block, Teflon Tape on the Brass Barbs, plug the fill tube and add about 3oz of Glycol Antifreeze, and 1oz Water Wetter per 1/2g.
Use a single 120mm fan preferable sucking and if possible mounted 1" away on the heater core style rads with a shroud (tape and cardboard will work)