Thanks guys and Gabby, hopefully I won't have to change anything. If I get those two powerheads I'll have about 7,500 gph of flow total in my tank.
Tony, I had it cut to fit by the plastic/acrylic company here that sells it and it does enhance the color a lot. It gave the tank more life IMO. About the flow, I will probably put a powerhead in each corner. I figured with about 7,500 gph of flow in a 48x18 tank, I should get good coverage pretty much wherever I put it(LOL). I'm kind of scared to use such big powerheads though. They might knock over everything. I may have to go with the smaller ones at 1500gph or 1100 gph. Can't decide, but will soon so I can order. Hopefully I can get to a computer tonight to post the pictures. Better yet, hopefully my computer should be back today from the US from being repaired and I can spend more time on RF after work as it has been crazy lately here and haven't had much time to be online. I guess we'll see...