what pump should i buy??

Hi so this is my current build. i have msi gtx980 gpu with intel i7 4790k to name the important bits.
my loop consists of phobya 150mm resovoir > phobya dc12 260 pump > xspc 240x30mm rad > EK waterblock > xspc 240mmx30mm rad > EK gtx980 gpu waterblock > back to resovoir.
so i want to swap out the resovoir/pump combo for something better. the current setup is easily audible from other rooms. its fine when i have a headset on at least but i wanted a water cooling setup to have it silent.

so currently i have my heart set on an alhpacool lighttower as it will fit perfectly in my case:
http://www.pccasegear.com/index.php?main_page=product_info&products_id=25475&cPath=299

and im thinking an eheim 1046 or 1048 pump but i can only get 1046 from PCCG australia. is 300lph enough?
http://www.pccasegear.com/index.php?main_page=product_info&products_id=26402

i can also get an eheim 600lph off this australian aquarium website if 300lph is not enough. but im not sure if i can get the right fittings to go with it. and will this be louder?
http://www.guppysaquariumproducts.com.au/eheim-universal-pump-1048.html

appreciate any opinions or alternate reccomendations. cheers

IMHO the Swiftech MCP655 is a great pump & it is very quiet provided there's something like HydrX in the water. I use the MCRes-Micro res.

Swiftech MCP50X. You can control it via PWM to cut down on noise from the pump.
It's honestly the best on the market, and won't break the bank either.

Having used both a D5/MCP655 and a Laing ddc it really comes down to what package fits your setup better. They are both excellent pumps.

my issue with the swiftech mcp655 is that is too big and will not fit in my case.
the swiftech mcp50x will fit but i can only get from america which will be like $40 to ship and the exchange rate too which will pretty much make the $70 pump into a $140AUD pump lol...
thats why im leaning towards an eheim pump. it has the perfect layout and have a good reputation of being quiet. im just not sure if 300lph is enough.

300lph is when it's on level ground and no restriction. A WC loop has high restriction. What we end up with is .5 to 2 gallons per minute in most loops, 1 GPM is typical and just fine.

You need to look at the head pressure, the higher the better flow rates. The pumps your looking at are probably fine, a bit noisy and really out of date in today's WC world.

I'm sure the eheim will suit you just fine.

Is there a way i can check how much head pressure my setup has now?

If you can't fit a D5 in, then there is no way you will fit an Eheim. With the limited space that appears to be available I would be looking for a DDC PWM and res combo. Like the EK DDC X-res

All DDC's are pretty rare in AU though, because the D5's are so popular I guess. pccasegear might be able to get an EK DDC res in for you. Or you could buy separate
http://www.pccasegear.com/index.php?main_page=product_info&cPath=207_160_296&products_id=29238
https://www.ple.com.au/ViewItem.aspx?InventoryItemId=615990

A DDC combo res is your best bet. I think XSPC has a Proton DDC combo or EK.

That's complicated. It's done with the pump removed and a special measuring device attached that measures the fluid pumped vertically up a specified tube. You can Google it.

Head pressure is a measurement of the pump, we don't want a low cheap aquarium pump nor do we need a expensive industrial pump.

The 1046 you picked is fine. The DDC series, a 35x or a 50x would be fine, as a D5 PWM would be fine. A D5 vario, even cheaper is fine. You have to decide how to fit it in the case and what you want to spend.

You got all the info you need.