Fuel tank replacement options opinions needed

[Silvermax]

Hello,
I had to throw out both saddle tanks on my newly aquired 1976 V-20.

I have the original 1976 Chrysler 135 and had it repaired and running great now, but was thinking of leaving out the saddle tanks and getting one large neoprene tank to put on the floor along the transom and even place a cushion seat across it, or a tackle/bait cutting tray arrangement? I do not know what else to do, and I wanted at least 40-50 gallons capacity if possible.

Thank you for any ideas and opinions.