There's already a Bouncer Charger on L4DMaps, although it's an old model and the rigging/bones do some weird things.

The Survivors should be relatively straightforward for somebody with experience, so long as you can find anyone experienced and interested.

As for the weapons save for the wrench, they would require or at least could really use custom melee animations, and so far I've only seen one mod that maybe kind of has those (Splinks' Master Sword & Hyrule Shield). It may not be possible or just very hard to do, so I wouldn't count on those being either quick or well-made.

i've tried to use the Bouncer, but my game keeps crashing when I use it, and nothing is blocking it...