Need sump advice

I have a 20L and im planning on adding a sump within the next month. I am going to have 1/2" plumbing. The sump with be a 20L as well I am going to drill the tank with overflow. I was just woundering what kind of pump I should get. Also I was planning on drilling a 10g and adding to the sump for a fuge, will this work?

just one of the pumps I was thinking of. I might just go to lowes, I work there we have a bunch of waterfall and pond pumps but im not sure how to hook up 1/2 pvc to them.
http://www.fishtanksdirect.com/Mag_5_Drive_Pump-500GPH.aspx

 

I would be careful of waterfall and pond pumps, I think most have brass internals which would be very bad for your tank.

 

Didn't even know, thanks for that. how many GPH do you think for 20, I was thinking around 600. I will T the return flow so the current wont be too much. Although my current powerhead is around 300 gph and its alot, though the flow is pretty much a just cause the outlet got broken in half.

 

I have that pump on my 20l sump and alot of people run it works great. Melvsreef also uses them.

 

I got a return pump from Lowes, it is a 500 GPH and I just ended up purchasing a Vis Aqua from Dr Foster and Smiths. The Lowes pump works great, but it is VERY LOUD. I cant concentrate it is so loud. So............Ill sell you my pump if you want