Help a noob join the club!

hi guys, ill cut to the chase, this will be my first WC setup ive done alot of research and have decided to do 2 seperate loops with the gpu loop split

havnt bought any of the gear yet cept the case, customized antec 300 (side window cut out, holes cut out on top for water hoses to enter, exit)

it will be i7 920 @4ghz, 2x 5970 OC to 1ghz hopefully (waitin on reviews etc). corsair 1000W psu, ssd drive, 3x2gb ram, average HD. mobo asus rampage 2 extreme(do u recommend this mobo?)

i will be buying the whole pc setup around easter (4 months) but will have the whole WC setup ready and waiting

all fans coolermaster 2000rpm. pretty quiet, no speed control. all radiaotrs with shrouds
loop1: tank -------> pump--------->apogie i7 block--------> PA120.2 -------->tank

loop2: tank--------> pump--------->Y splitter 1st exit------> 5970 ----> PA120.3----->tank
Y splitter 2nd exit----- > 5970----->PA120.3----->tank

as u were probably asking urself, yes i am mounting all the rads, pumps and res externally (directly above pc mounted on wall! lol). a few questions what pump sizes to get, mainly for the split loop. i imagine the hose length of loop 2 with be around 2.5 metres all up (to be safe). can u guys recommed a beast that will handle this loop? also the radiator sizes. the 120.2 is already in the mail for the cpu, i should be right with that yeah? do u think the 120.3's are overkill? i dont mind spending alot on these rads or having overkill as i want to take care of my pc's hardware rather than save a couple of bucks. after this build wont be upgrading for a while so i want it to last.

incase u are wondering why im building this rig, im an armed assault 2 enthusiast and want to play the game very smoothly with high settings. my current q6600 at 3.6, 4870 just isnt cutting it. also since i learnt to overclock my current pc i have become fascinated by OCing lol and i guess i just want to have a beast of rig that is WCd.
thanks for any help

Edit: incase its a little hard to understand, yes there are 2 seperate PA120.3's

Run the video card loop in series. Splitting the flow doesn't help because the water temp anywhere in tjhe loop is onlt about 1 c different. Less fittings less hassle in series. better flow over the parts too.

the rads are going to be mounted above the comp on wall. yeah arma is not yet optimized to its full potential but it will get there eventually hopefully, same thing happend with arma1, my montior is a 22inch benq. as for the case ive already bought the 300 as the rads are not internal and i also read that the cards will fit, does it really matter if its a tight fit?.
thanks for your thoughts i will probably run the 2nd loop without a splitter after that info but dont like the idea of warm water comin out of the 1st 5970 and into the next so tank------->pump--->1st5970------>1strad----->2nd5970---->2ndrad--->tank