Sump plan

First off sorry for keep bringing up my sump/fun questions. I wanna make one kinda like this.

My question is would it be fine to put a bag of carbon in the return area and my skimmer and would it be good?
Also I will be putting it in a 20 gal tank I have sitting around.
Also cutting. What method do you guys use? And for those teeth how should I do them. I have access to just about every tool. I have been thinking of using a dremel.

 

I think it would be fine.
I swap out my carbon and phosphate remover bag every few weeks and keep it at the return of the remora skimmer. This way it gets plenty of flow through it for optimal performance. As far as to make the slots for water to flow through - teeth - I would use a router.

 

I am going to use a 600gph ebay overflow, mag drive 7.
My other question is about the return. I dont have room for a surge tank. Should I just bolt on a tube going on to the tank or? I could rig up pcv that splits that goes in a t then have it go out 12'' on each side that the ends are caped. and drill holes in it like some sort of sway bar.

P.S. I finaly got my bounus from work woot!! Bad ass pico, sump, and new end caps(which allow me to run both vhos') and new bulbs! Woot