Bought a MTAC IWB from these guys, its awesome. After wearing it for a day and finding the sweet-spot, it feels great! Even with a T-shirt it concealed my Sig 229 very well...
http://www.comp-tac.com/catalog/product_info.php?products_id=95
http://www.comp-tac.com/catalog/product_info.php?products_id=95