Is there a site which has a good collection of recumbent bikes, still for sale new, to compare?
There is not a site available (that I am aware of) that does such a thing.  Bicycle Blue Book might be close, but they don't give you the ability to filter by bicycle type.  Somewhat unrelated, I submitted a suggestion to them that they add that feature to their site.

What's available is often not as important as what's available at your LBS.  I suggest anyone new/getting into cycling pick an LBS and start developing a relationship with them by purchasing a bike/trike/bent from them.  A local shop should be able to help you select a bent that meets your requirements, get it fitted and help you keep it maintained after purchase.