Look into a Rob Roy style sporran as they tend to have a large capacity because of their design,
Donnie at Wyvern Leatherworks makes a nice piece at a fair price.

http://www.wyvernleatherworks.com/st..._Sporrans.html


You can also try buzz kidder sporrans, I think the Inverness sporran will suit your needs.

http://www.buzzkidderoriginals.com/s...zzsporrans.htm