water movement(flow) isnt the same as a current, which is what I want to achieve. Kind of like speed and velocity, you cant have the latter without direction. You may be right though and it might work just fine but I think it would work better, aka more what I have in mind, if all the holes werent near the surface. I also do not want unsightly overflow boxes in my tank, although I may build a background for a river bank feel when the time comes, which could hide equipment.
Flow has direction FYI....
On the powerhead issue I don't think a Vortech I suggested adds much heat since the motor is outside. You would get the same heat from the water turbulence either way only thing you would add is some from friction which would be minimal.