Again, I want to emphasize that I wholeheartedly agree with those who have commented on the concept of full disclosure in a scenario such as this. I'm just looking for technical opinions on how this can be accomplished most effectively.
then you posted to the wrong mailing list. as you have discovered, this list is mostly used to air engineers' social, legal, and business opinions. try a technical/ops list, such as <your-router-vendor>-nsp@puck.nether.net, e.g. juniper-nsp@puck.nether.net or cisco-nsp@puck.nether.net. btw, may i presume you are trying to steer predominantly outbound traffic? inbound can be steered by only announcing the customer's routes to the desired provider, though that provides weaker redundancy. sadly, bgp offers poor knobs for this, asn prepending is popular, albeit grotty. randy