We measured the hatches out and had a local metal distributor do all the cuts... This was due to the fact that we had no saws to cut the amount of aluminum with ease. .125 or 1/8th inch thick aluminum is what we used for the entire boat. It is sturdy enough to support walking all over.
The seats are by Tempress and were $120 a piece, pricey yet sooooo worth it. they are very comfy and sturdy
The butt seat on the front is by cabelas and was $50 and is also a great buy. Really large and cushiony.