ok thankyou, i was wondering what the difference in the 2 pictured 180mm adapters was.

i dont like the standard 2 bolt that uses long bolts as in your pictures as like i mentioned they always need a ton of spacers. think my rear one has like 6 per bolt? seems alittle excesive to need that many for a mount made for a 160 mm rotor, just how much variation can one 160mm rotor have from another? i would think adabpter>washer>caliper>washer>bolthead would be more then suficent adjustment and would offer a much cleaner look and less parts that can shift around.
and my current front is the pictured avid post spacer as it came with avids and im getting away from them as fast as i can haha. but they have something like 8 washer per bolt......

on the rear however i have a 4 bolt is2p like pictured at the bottom and it still had long bolts. is there no variation that has longer arms at the " post " end for a beter fit? really seems these things would be designed better considering all of the advances in other areas of the bike.