The Philco passes thru. I bought mine online here:
http://www.solidsignal.com/dtv2009/how_to_purchase.asp
I've never seen it in a store. Wal-Mart carries a Magnavox unit, but Magnavox makes two physically identical models, one passes thru, the other doesn't. The info sheet that comes with your coupons should tell you which one is which. The pass-thru models are marked with an asterisk on that sheet. Wal-Mart may not carry the right one. I was fooled.
Amazon.com has a Magnavox:
http://www.amazon.com/Magnavox-DTV-D.../dp/B0013ZKZGU. Model TB100MW9. Check it against your info sheet.
Amazon also has the Philco, as I write, it's currently out-of-stock. The list of models here:
http://www.amazon.com/tag/coupon%20e...pp_cust_itdp_t. Unclear whether Amazon.com accepts gov't coupons or not.
Of course, buying them online means paying shipping charges. But you can get a Philco that way for sure.