Have never seen a converter box locally, much less on display. As I have mentioned on other threads. TV stores around here want to sell a satellite service so that they can get the residuals.
I could not find anything that I would want locally. As my coupons neared the expiration I ordered what I could find on line. One was defective and the other would conflict with my antenna rotor control. Then in order to get what I wanted I ordered good ones on line when they became available and paid full price for them.
Decide on features, make and model that you want, enter the make and model into a search like Google. Then be careful who you deal with and if they are even in the US. A lot of scams are coming out of Canada at this time. The FCC website was listing the companies that they caught that have not been what they should be. They also had a list of the big merchandisers that had been fined for claiming TV sets to have digital tuners when if fact they was not. I have not checked those lists for a while.
Buying from a local store is almost always best in my opinion and it is nice to support the local company. Also a lot easier to return it if it is defective. If you have a local store that wants to do business.
I think it best that we do not recommend a particular place to buy. Just because I liked the service does not mean that you will. I selected a company online that had what I wanted in stock ready to ship. I also wanted that company to be set up with PayPal so that I did not have to give them my credit or debit card numbers. I ordered from a company that did both of these plus they did not charge extra for shipping.
Every store that I have been to has been sold out of them. Is there a website I can go to that will show me when a certain store is going to get a shipment of converter boxes in? Also, I haven't received my coupon yet so how much will it cost me without the coupon?