Firstly:

Secondly:
There is no complete list of new ships that have been made. They are really scattered around. HadesCombine used to have a lot, but now its down. So
www.freespacemods.net is probably your best bet. Installing them should be pretty easy, the POF file(s) go in data/models/ (probably of a mod directory), and textures (all the PCX/DDS/JPG/TGA) go in data/maps/. It also has to be in the tables somewhere, either pasted into ships.tbl (in data/tables/) or as a modular table (many of the mods you download will come with one of these, put them in data/tables/ as well).