if you can drop me an email fenderrick AT hotmail.com then i will be able to send some links to some articles etc... only they contain links to other shops etc so i cannot post on the forum
sorry
but in general you want to have a ballanced system
for example a 1500lph pump simply has too much flow... always go for head presure over flow. as the kind of pumps that produce 1500lph ( litres per hour) are not designed for high resistance applications such as watercooling.
in a nutshell ( and im truly not saying this becasue ive got one ! ) the best pump to go for is a MCP600 AKA Aqua extreme 50z. you will see this in the links i send you
if you have ever heard of cathar, this is the pump that he reccomends as the jack of all trades and in most applications is the best one to use... obviouslty every rig differs but this pump has always been a clear winner.
its high pressure and low heat dump ( only 8watts)
heat dump form pumps MATTERS if the components you are cooling have LOW heat watt ratings, say if a CPU was putting out 50wats of heat, and your pump is putting out 25 ( totaly made up scenario btw) then automatically your pump is accounting for 50% of the heat in your WC rig.
but since you will be cooling a lot of parts, the percentage of heat that the pump will dump suddenly becomes smaller... say your now trying to cool an over all 200 watts, and your pump is adding another 25 to that... now the pump only contributes towards just over 12% of heat in therig there for you can afford to use a higehr pressure pump with a little more heat dump.
now that alphacool pump you mentioned puts 17w of heat into the water, and has a high flow rate.. id steer away from that pump if i were you.
but have a read through the links i will send you and see how much you learn from them
Rick