Though not an army, at least something to play with until one is released.

Monolith Designs sell figs in 36MM:
http://www.monolithdesigns.co.uk/cliffhanger.htm

Crooked Dice:
http://www.crooked-dice.co.uk/wp/product/simian-minions/

Eureka had a complete product line. They pop up on eBay.

Ainsty Casting has figures
http://ainstycastings.co.uk/product_info.php/products_id/946/osCsid/a5a6825b26526245da2c1acb44594871

Sgt Major:
http://www.sgmm.biz/search.asp?keyword=Apes&search=GO

Impact make apes that might be converted
http://www.impactminiatures.com/?option=search&search=Apes&Submit=+Search+

Same with Fantasy Flight
http://www.fantasyflightgames.com/edge_news.asp?eidn=2275