I dunno whether this will be helpful to your endeavours or not, but if you know how to write plugins I'd try using SourceMod itself for actually giving players weapons. The ability to do so through Hammer/maps is very limited because TF2's item system is so sophisticated, so you can't set up weapon attributes without access to code.
An easier way if you're able to write a plugin would be to place triggers into the map named in such a way that the plugin would be able to find them (for example, a trigger_multiple named "trigger_weapon_xxx"). You can then replace the "xxx" with a TF2 item definition index, and the plugin can hook into when players touch the trigger, find out the trigger name, read the index and give the player that weapon.
If you don't have the ability to write SM plugin code, the above method sounds like it would be good enough if you know that the "sm_givew" command will be available.