If you get the dimensions on the filter size you can order one from summit or jegs. They're honestly about the same price almost anywhere you look, Summit makes it nice to look that sort of thing up because you can specify every dimension.
I ordered an AFE synthetic media filter for my C&L Racer. I don't like oiled gauze filters, they let in a LOT of fine dust.
'05 Mustang GT Premium
CMS Stage 1 cams, C&L Racer, Lito tune, Jeg's oil sep, CMDP, SR UDP's, JBA stainless LT's & catted H, Magnaflow resonators, MBRP axle back, BMR springs, Koni STR.T, BMR LCA's & backets, J&M upper & mount, J&M Al panhard, DIY panhard brace, Steeda Tri-Ax, smoked corners, Raxiom Vector tails, Brembos, S550 GT Premium wheels, 2010+ door panels