Gamut!, LoL...
Blackeagle what are the watt ratings for the 20 series?,(the MD20RZT looks good to me).
120mm fans are ALL quiete when run at 7V, it's when(& if) you want to put the power up they'll get loud. YSTechs are cheap and powerfull, Papst are the best build and quiet, Panaflo are quiet and well made. look for the highest static pressure rating, prolly wont mean much @ 7V but there you go!
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The Deeps and Abyss are cheap in the UK especialy compared to BIX's. how much would you have to pay for shipping?, how much tax?, could the tax be avoided if it was sent as 'parcel rather than an 'order'?, I know nothing about shipping :shrug:, but if I can help let me know
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Certain Cu heaterCores are perfect for 172mm fans, fitting them incase is another matter!, you could always solder 14mm barbs onto a BIX as well...
BillA did an article at overclocker.com on Rad performance, on optimum flowrates for different rads, helpful to work out if single or parallel is feasible. I'm not sure where the point of diminishing returns starts on your average block, you'd need to see a graph of the specific block(s) to be sure. even then you'd need to know what flow is achievable with a given pump for your chosen setup, but the higher the pressure/head the closer the chance of achieving(or getting close to!) the stated max~flow rate...