Cobra rear brake question

I'm also considering just buying the front Bullitt calipers from BFR*, and a pair of Ebay Cobra rotors now. Right now with the 95GT front and Fox rear drums my pedal is soft, but bearable, if I'm interpreting this correctly I went from:

this:
87-93 60mm calipers
-2827mm^2
-5654mm^2 x 2 calipers

to this:
94-98 GT/V6 calipers : 66mm piston
-3421mm^2 each piston
-6842mm^2 x2 calipers

Which is a difference of 1188mm. However if I put Cobra calipers* and disks on the front there will only be a difference of 502mm. Which will get the pedal feel back closer to what it was, plus I get the added braking power of the 13" brakes. I would still be running rear drums though, has anybody done this before? I eventually will get rear disks (probably the NRC kit), but doing all of it at once is more then I want to spend right now as this isn't the only project I am working on.

Thanks

* http://www.buyfordracing.com/shop/product_info.php?products_id=689{11}24
 
It's been done, and your way of thinking is correct. The mc has no idea what brakes are on the car. The closer you get to original caliper piston surface area, the more similar brake feel will be.
 
Sorry to hijack this thread but I have a similar issue, wondering what to do with the rears. I have a 91 GT, and right now I have 2000 GT Brakes. Front spindles are out of a 2000 GT as well as the rotors and calipers both front and rear. Im running sn95 axles out back. I just converted over to 13" rotors with Cobra Calipers up front, now Im needing to add some 11.65 rotors in rear to match. What all do I have to do to make the 11.65s fit?