the vibrating of your pump is solved by glueing shaft to impeller, as gmat pointed me out. i did it, and it works. problem 1 solved.
i've looked into innovatek alot, they don't sell larger fittings. maybe u can find larger fittings in a hardware store that screw/fit on your innovateks. there is alot of talk between 3/8 and 1/2 tubing. i would like to c some hard proof that one is better than the other. if u can get all fittings 1/2 then your off, but if one component is smaller, the weakest link in the chain, so to speak. if u bought innovatek, then maybe you're from germany. well look into the site of
www.aqua-computer.de , very professional site. u gotta love em cuplex wb's , and that airplex rad looks extremely nifty for a nifty price.
concerning rads, goto local autoparts store, they have catalogues with 100's of rads + dimensions. i wouldn't know of a better place to search the perfectly dimensioned rad for your situation/case. i bought mine over there and it cost 35€.
i now have 2 radiators in serie, one maze2 with 3/8 tubing. one eheim 1048. i got temps under load never over 40°C with 120mm's running at lowest speed (inaudible). very happy, it wasn't exactly a cheap setup, but if u start to buy em black ice rads, then its getting expensive...