my original idea was for CT's to have only pistols at first and the T's only a limited amount of knifes (say 10 of 15), as t's escape the CT's are then granted Shotguns > SMG > Rifles etc in an escalating fashion, potentially there would be a 'main' exit with two or three possible ways of opening it and or a side exit and a secret exit (Tunnels etc).
As for T weapons a few stashed pistols, an SMG that requires 2-3 people to get and of course ample knives, potentially all t's also start with smoke grenades (to hide who has knives).
The server size should be about 30 for a good game