The problem with the cheaper kits is that they're actually very little better than a good air cooler (maybe 2-3C).
The more expensive stuff will get you up to a 10C drop over an air cooler in my experience.
A good quiet air cooler like an Arctic Cooling Freezer Pro costs under £20 so you're paying dearly for a small improvement on the lower priced kits.
The other problem is when you want to sell the kit and upgrade. Very few people will take Thermaltake off your hands, whereas you'll only lose 25-30% on Swiftech stuff if you put it on Members Market.
Bits do come up quite regularly on MM as people upgrade, so it might be worth your while posting in the wanted section and see what comes out. Someone is almost bound to have a Thermaltake Big Water they want to offload.
I know it's not the advice you want but I've got a Coolermaster 80mm kit lying here and I honestly wouldn't risk the embarassment of selling it to some poor sucker who'll have the same high hopes I did. That was actually worse than an AC Freezer 4 unless it had 2 push-pull fans mounted on it. The 120mm kit is a bit better 2C drop with 1 fan, 4C drop with push-pull.
But my new Koolance PC3 kit gives me a 10C drop out of the box, although it does have a top mounted 120x240 radiator
[Edit]Just noticed your post count, but the advice generally hold good. Post sensibly, but post often and get your MM access for some real bargains[/Edit]