I have developed a lot of recipes that are based on original recipes that include meat...
Seitan is a good one because if you make it yourself you can put it in virtually anything to absorb the flavor of whatever you choose...VERY labor intensive though, is a lot of flour to wash for a little bit of product. When you purchase it commericially you have to take whatever they give you, the only one that I ever really especially cared for was in peanut oil...I could eat that stuff by the jar...
As far as soy sausages go, which I used to use in meat pies all the time. There is a company out of Charolettesville (sp?), Virginia that makes the BEST!!!! I think their website is
http://sunergiasoyfoods.com or some close variation thereof...
Most of my personal chef clients are veggies in one form or another, so I do a ton of them, if I can help you with anything feel free to drop me an email...