Cutting out the seats- It all depends on how much space is between your gunnells. Think about it, g3 and mudbuddy comes without seats. I opted to leave my rear seat my buddy didn't. We both have different boats, he has a triton and I have a alumacraft. Our distance between our gunnels are different. Mine are closer than his, he installed a gunnel he fabbed to take up the void. On my boat the distance was only 3 inches longer than the other gunnels. We both installed 1/2 marine ply floors the full length of the boats. These are semi permanently mounted. The wood floors eliminate the flex by tying it all together. I have a 25 merc 2 stroke on a 16 ft boat, he has a 40 yama four stroke on a 15 ft boat. Neither of us have experienced any cracking or stress fractures til date. Both of our boats are driven hard and very very frequently.