I'm glad you liked the rec!
Well, fandom-wise I'm mostly in Due South and I don't know all the ins-and-outs of Jossverse but some places to start:
Deconstructing Wesley which has fic but is also just all about Wesley:
http://www.burntcopper.com/wes/fic.html

From the Deconstructing Wesley site's links page I got the Wesley Fanfiction Archive which might be just what you are looking for:
http://wesleyfanfiction.net/archive/

There is also the BtVS Slash archive at:
http://www.geocities.com/btvsslash/

There used to be a Wesley fuq-fest or similar challenge site, but I couldn't find it in a google search.
Good luck finding fic!