ahhh Brie and Alyssa....good times indeed.
4 hands is a great feeling if the massage and build up is done well, and then to enjoy 4 breasts and 4 ass cheeks and everything else can be exquisite. that being said, 4 hands from 2 uninterested and mechanical jackhammer specialist aunties in an AMP would not be a great experience at all.
If you're going to try it, find two girls who want to do 4 hands together - not every girl in this industry is interested in "letting go" in front of a coworker. and as always, YMMV
To answer your questions...if you have a favorite girl at a shop/independent group, ask them if they have ever done four hands, and also who they would be interested in doing it with....i have asked this before and sometimes their choice doesn't line up with mine! And when you're in the midst of all that flesh, i find it polite not to play favorites if you know what i mean. nothing kills the mood like making one of them feel inadequate. encourage them to appreciate each other, this may be the first time one of them has been naked with another woman - might be fun to encourage them to try something new...and most importantly - have fun!