I don't believe SD equipment is available any longer. If you have it, you can obviously keep using it, but no new orders are being accepted for SD equipment.
i didn't order one, but I just got sent one as a replacement for my Motorola 7100 HD box. When I renewed my 2 year contract I was told I had the wrong box and they sent me a 2500 SD box. Needless to say, I'm not pleased and the drama shall commence .....