.Map :: MoHAA Mapping

can u put custom skins in singleplayer maps and if so, when a person downloads it do they need to download the skins seperatly

Yes you can.
For multiplayer skins, there is a tik file found in models/player.
Single player skins are similar but the tik is found in models/human.And at the bottom of the tik you add the /*QUAKED part so that it can be seen and used in radiant.

You can also use the player skin(multi-player & fps-first person)versions for your player skin in single player maps by adding the following line to your map script after level waittill spawn

setcvar g_playermodel yourskinname

Put all the tik files,shader files,and textures in the proper folders in your maps pk3 file.No need for a seperate download.