You're probably not going to find a used K&N, just get that new. The dude with the evo 8 had a new type-s for sale on tbdsm for-sale-forum, he wanted 165 for it which is five bucks off racing zone's price, but maybe he'll have gone lower by now, I couldn't say. I don't want to criticize your wishlist, but you could probably find better mods for your money than the air/fuel gauge and to a lesser extent the turbo timer. Both are cool electronic gizmos, though, so I can understand your motivation for getting them.