where to get returns drilled.....

[spikehs]

I am setting up a 50gal tank (36x18x18) and i wasn't quite sure where to get the returns drilled. I currently plan on have 2 3/4 inch returns drilled somewhere...My rock structure will be to rock piles in each of the back corners one for sps and one for everything else. I am going to be hooking up a scwd to it to provide some nice random current (along with a 1000gph pump). I had 2 ideas

1. get them drilled on the back of the tank, the point the returns to each rock pile...

2. get on on each of the side panes...i was leaning towards this way as it would seem to provide more of the back and forth current that i was looking for...

any ideas?

Sean