With most grinder/ejector systems you will need to run a vent pipe through the roof of your house. You can not tie into any other vents either, so you will need to run a separate vent. I've been looking into doing this for a bit now in my basement. If your house is already finished, like mine, and you have no options to run a vent through the roof, you can look at the Saniflow Sanistar and Sanicompact. Neither one requires a vent since they are self contained. The Sanistar is wall mounted, which is what you are looking for, but you can not add a sink to it. The sanicompact is floor standing, but a sink can be added, which is nice. Just go to the Saniflow site to see them. I tried to post links, but unbelievably I don't have 3 posts yet!
-Matt