As for getting the models, you can extract them from your CS:S files.
Download
GCFScape, go to your CS:S files (..\Steam\steamapps\common\Counter-Strike Source\cstrike), and open the
cstrike_pak_dir.vpk with GCFScape.
On the left side, expand the
models folder and then select the
player folder. You should see all the player models in here (
https://i.imgur.com/COpVePt.png).
Grab the
dx90.vtx,
mdl,
phy, and
vvd files of the model you want. CS:GO doesn't seem to be using dx80.vtx and sw.vtx. You'll probably need the materials for those models as well, so head over to
materials > models > player and get the materials you need. Extract the models and materials to your CS:GO server, remember to keep the same folder structure.
I'm not sure if these models will work in CS:GO right away, you might need to recompile them specifically for CS:GO.
If that doesn't work out for you, you can always try extracting the models from
Classic Offensive. Those models were made for the CS:GO engine.