Have you tried buttler creek for the flip up covers. I also seen a set (with soft rubber sleeves) at Gander Mountain. I think they were like $6.00 a piece. Look around on ebay. I know I've seen some fake (meaning non-Aimpoint) covers for like $3.00 a set.
Also the rubber thingy was up of ebay also...$20.00 with a spare cap.