yes set up a res file. i used crossfire to download my servers custom models for the bots.
heres my res file for crossfire....
// .\crossfire.res - created with RESGen v1.00
// RESGen is made by Jeroen "ShadowLord" Bogers
// URL: http://www.unitedadmins.com/mapRESGEN.asp
// Res creation date, GMT timezone (dd-mm-yyyy): 27-07-2001
// .res entries:
i only use crossfire for the model downloads but you can add the models downloads to other maps(all the maps in your mapcycle if you wanted).
if you are taking advantage of sv_downloadurl make sure you upload the models and the res file to your webserver also.