Which carrier and plates did you decide on and why? Most people I know have the Banshee, some with and some without the side plates. I haven't seen anyone carrying the new Level III+ Lightweight plates yet.
Also, take a look at Ultra High Molecular Weight Polyethylene (UHMWPE) plates, such as the Link Removed and the Link Removed. At only 3 lbs. per plate, you save 10 lbs. in total over two 8 lbs. AR500 steel plates with the same level III rating.