The upgrade bug has bitten you as well Randy? Since no one has replied yet I thought I would to give you some company.
I guess the only way you would know would be to order a pair and take advantage of the 30 day return policy. I think monos would be a waste for the rears since they do not get that much action during movie watching as you already know. I would stay with the front three for any type of improvements.
Any dealers nearby that would be willing to loan an amp for the weekend for you to try out? That might save you a few bucks shipping the outlaw monos back if you don't notice any difference with a loaner amp.
If it doesn't make a difference in your system then an ep500 probably will.
