Ronco supplies Raritan tanks...
And Marine Sanitaion also gets their tanks--except for SeaLand--from Ronco. Ronco has FAR more shapes and sizes than any other mfr, so if nothing in the Ronco catalog will fit, you're not gonna find it in any retailer's catalog either.Custom + rotomolded always = VERY expensive. If none of the Ronco tanks fit, you'll be better off going with a good quality welded plastic tank. There are a couple I know of:http://www.gocctech.com/marine/boat-tank.htmhttp://www.triplemplastics.net/Otoh, in the 10+ years we sold Ronco tanks, I only had two boats we couldn't fit with one of theirs--and in the approx capacity the customer wanted--so maybe we should discuss it a bit before you have a custom tank made.