Well here an small tutorial how to convert most of the characters to playermodels.
1. open an character model that only contains attachments, for example
objects/characters/human/asian/nk_soldier/nk_soldier_jungle_light_leader_04
.cdf
2. in the attachments tab remove all attachments. be sure there's no mesh left and save it as a new file. for example call it "newcharacter_fp3p.cdf"
3. now find what character u like to use and open it. u can use almost anything, but sure that it has all animations on the body and seperate hands models and head.
u can export all attachments u like together as an .atl file, or choose to manyaly pick different parts later.
For example i used :
objects/characters/human/us/officer/officer_caucasian_02.cdf
4. finaly remove all attachments and save the body as an new file, for example call it "newcharacter_body.cdf"
5. now open the "newcharacter_fp3p.cdf" and create a new attachment. give this "body" as name and set it to "skin attachment".
6. now press the import button and open the ,atl file, or manualy add attachments in the attachments tab if u diddnt export these.
u might need to change the head, hands and maybe some other of the attachments to "skin attachment" as well.
U should now have something like this:
7. now edit player.lua and change the clientFileModel path to your model.
8. restart sandbox2, open your map and have fun