That's an awesome tank. Wish I could find one like that around here for that price. 2X4's, nice 3/4 underlayment plywood that takes stain nice & don't forget to put plenty of internal support via vertical 2x4's attached to the solid horizontal top 2x4's under the plywood. Make sure there are at least three solid lengths of 2x4's the length of the tank for the platform under the plywood & the same for the bottom. Measure from top left corner to bottom right corner to make sure its square, same with the other side. I used a ratchet strap on mine to pull it the quarter inch it needed to go & hold it in place to screw the supports into place with the internal supports going from the top corners to the opposing bottom corners. Use like three inch decking screws or three & a halfs & sink em right in. Don't use sheetrock screws or the coarse black screws, they crack under stress. Once I had mine all together I covered it with that underlayment plywood which was a little over forty bucks for a four by eight sheet. Expensive but once I added the black stain it looks sweet. I just need to make the doors, add shelves inside & its complete. The plywood adds a lot of support. I used black trim nails to add the plywood & counter sunk them a hair with that trim nail punch tool. Don't forget to add a hybrid foam mat to make up for any imperfections. Hope this gives you some ideas man