I use "maxi jet" and have not had any problems with them clogging up or stoping. I havent had to bang them to get them to work either. there also fairly cheap off the internet.
I had a rio powerhead in my last tank. Call me crazy, but I blame it for cracking my glass. Suddenly from nowhere, the front payne shattered. not in the corner, not at the seam, but right in upper corner next to the rio. at the time i noticed the entire top of the powerhead had blown off, i didnt think anything of it. i wanted to save all i could so i put my LR and fish into a big tupperware bin, and then i got that rio powerhead with the top off , and i put the top back on and put it into the tupperware. I plugged it in, and later I went to reach into the tupperware and it shocked the hell out of me. Somehow the rio had a short, and was shocking everything. its all i could think of that caused the explosion on my tank. maybe it was just coincedence, who knows. but i know i'll never own another rio.