Its not so much a union rule as it's a set experience/etiquette rule. People are in charge of that gear and accountable for it, so it's always best to ask to use it. Snagging a sandbag from the grips without them knowing so you can prop open a door is a no no because at wrap, some poor grip has to look for that missing sandbag.
Talk to the local Grip and Electric Rental houses in your area. Ask them if they could use a hand at their shop cleaning up or whatever. Put in some free time at their shops and that will start building the relationship.
5/8ths rigging kit should do the job for a 8kg camera, but if speed is the key, then sticks is best, or a bungie cam system, that way you can actually do some moves and the bungie system could absorb some of the bounce.
I've known half a dozen people go to Full Sail in Orlando and none of them have been able to get work in the biz except one guy, the guy who gripped. He started working immediately after school.
I too am looking for a good central place to sell and purchase used gear. Sadly the best I can find is gear here and there on Craigslist, eBay, and then random Grip and Electric Rental House sites.
Do you have a picture of the panel for the 6500 Honda? We have two at the G&E house I work at. Ones got camlock coming out, while the others got 240V twistlock coming out. So they can definitely handle a couple of 1200 and Kinos. We use them to run a 4k and 1200 at the same time.
The biggest issues we ever run into is the fact that the electronic ballast are really sensitive to how much voltage is coming down the pipe, so if something isn't striking be sure to check the voltage is pretty close to 120. Then we just tweak the barber colemans to get it where we need it to be.
Or you can buy some gelly rolls. We use them at our grip and lighting shop to organize scraps into precuts.
http://www.advantagegrip.com/gelbags.htm
Advantage Grip makes some pretty nice ones and they can make custom sizes if you ask.
Also remember gels are expendables, so eventually you throw them away.
My friend shot a music video using the 5D MKII and the HVX200 with a RedRock 35mm lens adapter.
You can see the video here. I think they mixed pretty well.