Lets start with the pump. Mags are great. Ive used anything from a Mag 3 to the 18, you must have something underneath them. Right now under my Mag I have a peice of foam but you could use a mouse pad.

As for the water splashing id extend the pipe into the water or ad filter socks but you really do not need the 90s you have. You can also ad foam on the inside of the door to cut down on sound coming from everything in the stand.