Specially made would be the way to go, as far as I can see. The question that comes to mind, though, is why? This car is pretty light, and unless you intend to race it, the only real reason for this mod would be for looks or bragging rights. If you keep the solid discs cool, they'll do just fine. You could use the slotted and drilled ones, I guess. I'm curious. What's your reason for wanting this modification?
We're putting four pot calipers on a "full house" Bugeye right now, and went with solids. I see no reason to worry.
Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon