How do you choose a DCC decoder?

I have recently decided to switch to DCC and I think i will go wwith the Prodigy advanced, but how do you pick a decoder?? There are so many. I mostly own Atheran, someDCC ready and a few that are the old style. I have 2 proto 2000 that are dcc ready. I can solder pretty well, good enough to soulder one in i think. Does it really mater which one I choose?
Also about sound…A couple of my favorite engines I want sound. Which one is a good sound system decoder. You see alot on ebay but which to choose.

Right now the choice of sound decoders to intall in a locomotive yourself are limited to Soundtraxx and a generic MRC sound decoder that does not get great reviews, but is a lot cheaper. MRC just announced new sound decoders, QSI are about to sell decoders for installation, rather than just preinstalled in BLI et al. Soundtraxx is about to release the new Tsunami (about being a relative term as they have been “about” to do this for about a year). Digitrax are rumoured to be close to releasing sound decoders. Anyway, for sound decoders I think it is a good time to wait and see what shakes out. At least that is what I am doing.

As for regular decoders. Some decoders are made specifically for locomotives. Your BLI DCC ready may be candidates for these. You can check application lists on the Digitrax, NCE and TCS web sites to see if they have specific reccomendations. For the Athearns you want a decoders with a wire harness that you can solder into place. There are many choices for this. You can spend as little as $12 on a basic Lenz decoder with a single light function, all the way up to $50 for multi function decoders for all sorts of light effects etc. So the choice is often more about functions you want and price. Check out Litchfield station and Tonys Train Exchange and Loys toys. All 3 have installation suggestions. Also the Gateway NMRA web site has a section on installations.