I have these same cameras from Costco and switched out to 3.6 Mega lenses. This seller is the one I purchased from but looks like auction ended. You may be able to ask if he has anymore left.
http://www.ebay.com/itm/251182948807?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
The quality is actually clearer than the stock 6.0 lenses.