Just a thought...
I just purchased a Phillips model (don't have the model # with me right now) from Newegg and hooked it up last night.
It's the only model I found (in a limited search) that had dual coax connections. I have both DiercTV and Comcast limited basic cable (which delivers my local channels (including the HD broadcasts), so I had the need to protect two coax lines. Also ordered one for my grandfather as he has both Dish Network and Comcast cable internet.
Can't speak too much about performance as I only hooked it up right before bed, but I am curious to see if running the coax through it causes any problems. It was about $30 including shipping and came with two decent coax cables and a phone (RJ11?) cord. (Unit also has phone line protection (1 input, 2 outputs)) The unit looks a little bit cheaper than some other brands, but it has something like a 3240 joule rating and a $300k equipment protection warranty.
I may not remember to come back here to post any updates, so anyone who is curious may want to shoot me a personal message and I'll be happy to share anything I can.