I used to run the store bought type,,, had bad experience with AC dumping water when clogged then went to Whisper and some Hagen powerheads on UG filter and Magnum 350 and Emperor 400 all of those I was ALWAYS replacing impellers it seemed and the Emperor was noisy to me. So I have built my own for the last 2 filters, 10 yrs on the last one and just started a new one (pics of it attached) I run TAAM Rio pumps since they have ceramic shafts and thus don't wear. My current main pump Rio 2500 moves 650 - 700 GPH (on a 120 tank) and been running about 10 yrs now non stop.
largest one I ever built is also below,,, uhhh lets see 20' L x 10' W x 4' D and 3600 gallons of tank,,,,,,,,, HA HA!!
I own an excavation company and we install more complicated Septic Systems,,,, same thing though just bigger than you find on a fish tank.
So my vote is the DIY for SURE!!!!
