Quoted:
I think you'll have a tough time finding something "new school" for magazines of that type.  Best I can think of are the Canadian Pattern 82 C2A1 magazine pouches, which hold two 30-rounders with an internal divider and straps to aid pulling them out.  Pouches are fully enclosed and made of modern materials with waterproofing.  They can be adapted to MOLLE in one of two ways; one is by cutting up the Velcro straps for belt attachment so that they can be used with MOLLE; the other is to cut out the plastic part for use on the Pattern 82 belt, replace with ALICE clips and use an ALICE to MOLLE adapter.  They come in a very dark olive green colour, typically.  There are a couple of vendors selling them cheap right now.  Enclosure is similar to that use on pouches that are part of the M1956 system (plastic loop on the pouch that goes through a plastic slot on the flap with a web strap attached to the flap going through the loop with an extra piece stitched on to keep the fastener from becoming undone accidentally; IMO it's fast and quiet to use).

I think the AK stuff and 35-40 round 5.56 stuff is too narrow for use with these magazines.  Probably depends on the manufacturer.  I know that the South Africans made pouches that could be alternately used for magazines for 7.62X51, 7.62X39, and 5.56X45 weapons, like on their Pattern 83 webbing (which doesn't meet your specs otherwise, though).

Not my ad but worth checking out at $6 a pop.  Might get some for my BM59 mags.

http://www.ebay.com/itm/Canadian-Military-7101-Long-FN-C2-Pouch-Mag-Pouch-Webbing-New-82-Pattern-1343-/151903299807?hash=item235e2468df:g:a1cAAOSwhglTxrwK

Quoted:
HSGI needs to make a Taco "Grande".

Quoted:
I think regular HSGI tacos will work. I use them with 25 round pmags for my AR10, but a taco grande would be funny.