BlazingPhoenix
AAAAAAAAAAAAA
There's a unoffical version of Doom Builder that was released by "ChaosCentral" that has a DECORATE Editor built in, this should make mapping and monster/weapon creating so much easier 8)
http://www.chaoscentral.biz/downloads/DoomBuilder DECORATE Edition.zip
http://www.chaoscentral.biz/downloads/DoomBuilder DECORATE Edition.zip