how come no one mention macro series skimmer? i heard they are good skimmer too.. anyone out there have experience with tat. i tink they have models for hang-on tank skimmer and it comes with pump(not very bulky i tink).
red sea primz's design is slick for a small tank, but expensive.
regarding power head pump, i have tried ehiem PH. some models can be use externally(not inside water) AND internally. so if you have space constraint in your tank, u can put it outside tour tank. but it is very expensive and bulky. btw, if u decided to put in tank, dun forget to consider the fact that it will generate certain amount of heat into your water. just note to point out.