I called Holley to get more information on the product. They were helpful with a few questions/answers.
They don't do custom sizes, but will be producing more sizes in the future, but they don't have dates when. I was thinking for our tanks a long thin version that fits directly to the pump would be great. The fittings cannot be specified, they only make whats on the website. So there is only one version that would attach directly to a normal in tank pump, but that's not really the right shape (not long enough to go to the other end of the tank). But he did say you can put adapters on the mats and create different configurations and fittings......
Thinking about that type of solution.... might be two of the 8x3" mats ($139x2), one on each end of the tank, with some associated tubing and couplings (maybe $50?) to link the two mats to the bottom of the pump. Something like the following video at about 45 seconds in.
https://www.youtube....h?v=xuAlS3W90LI
As I see lots of pictures of modified tanks out there... I'm not sure what our tanks start with. There must be some basic baffles in the OE tank I would hope? Does anyone know what the OE internals look like? To do something like the above might work effectively but would have to get around any stock baffles. In the end, I'm not sure its worth it for a $400 US ~£300 solution which would end up a bit of an assembly any way. If I was running an eternal pump, or they had a mat that fit out tank better, this might be a great solution however... decisions, decisions.