Weapons and Monster respawn

I have this idea for my map and I was doing this rpg type thing on doom where I go into this big area and kill all the monsters and after I'm done I can leave and the monsters will respawn back so I can go for round two. I also want to make weapons respawn. I'm pretty sure this is possible but I haven't figure out how. I look at zdoom wiki but I haven't found any clues. Can any body help me out?

The more modern approach would be:

Have a look in the ZDoom WIKI : http://zdoom.org/wiki/SpawnSpot

After placing these SpawnSpots in strategic locations, you could use a script such as this one

script 1 (void)
{
    SpawnSpot ("DoomImp", 6, 50);
    SpawnSpot ("TeleportFog", 6);
}

to have another go around.

The script could be triggered by crossing a linedef with the special 80: ACS_Execute
or
you could use http://zdoom.org/wiki/ThingCount
in an OPEN script, which checks how many enemies are left standing, and when none are left, it would trigger the above script.


And the old standby:

As the first wave has been dealt with, doors open to reveal the next lot of enemies.

[edit]
I had some time on my hands, so I made this little example
http://files.drdteam.org/index.php/files/get/YPGjSysB3Z/all-gone-01.7z

thank you very much for the reply. Sorry for taking forever to reply back ^^; will try this out. Also look like the file is offline at the moment. Sorry for taking up your time. I will try this out