I'm interested in water cooling my machine. I've already got a new heater core from a local radiator shop for $20

It looks a lot like the radiators you get from Danger Den only it's half the cost and half the asthetics
Anyway, I'm trying to keep this thing under $150 budget. I've got two 80 mm case fans that could be used on the radiator. Would this be better than just using one 120mm? I've got tons of Aluminum tape and could eaily build somekind of shroud, but I really want to build the best system that I can afford.
thanks