Starting from level3 or 5 is gives you all you need, really. I even had more gear when starting from "5" savegame than when playing normally from 1.
If you really want to have a ton of loot, start in original level3, go to the secret boss fight (doesn't always spawn), and spend a few minutes thinking what to leave behind.
I'm disappointed Random Starting Gear is crap. Most weapons are strictly worse than their equivalents using the same ammo. It quickly degenerates into a knife run, because you have no starting pistol until you find a "second" one in level3. The exceptions are sspoon (higher damage per round, perfect accuracy) and fat john (very accurate shotgun with better penetration). These are the tradeoffs you might tolerate into the endgame... although mg3200-drm has a big, undocumented accuracy boost.
Nailguns are questionable even when used optimally.