I would call kaye at bills welder repair they are not that expensive. If your set on making your own go to tractor supply and get the spindle kits. They are about 40 bucks each. You can make the reel itself out of just about any size pipe. I have a set that are 4" pipe 10" long with 10" discs. They hold about 100' each. You can use Trailer flooring or high density plastic to insulate them from each other. Just bolt the reel frame to the plastic, countersink your holes, and bolt the plastic to whatever you want.
You can build an easy & inexpensive set of reels out of a pair of Setco brand fire hose reels. I got a pair from the local scrapyard for about 5 bucks. They have a little axle running thru the center on ball bearings. I made an A frame stand to mount them on out of 1" sq tube & some 12" junior channel for the base. Put some aluminum diamond plate on the sides so they looked cool. The set I made do not have the contact spool, they need to be plugged in. Not a real big deal, considering once you get your line out, you usually leave it out till the job's done. Besides, it only takes a minute to pull the pony cables out & set them up anyways.
What is nice about these particular reels is that they have a cast aluminum center piece that has 4 holes in it just about the same size as a Tweco quick disconnect. I welded a little piece of pipe inside the framework that lined up with the hole on the casting with a couple of tapped holes in it for set screws & fed the cable with the Tweco female end attached thru & just poking out of the pre made hole. They are fully insulated & you won't be getting shocked off of them. Bought some cheap bearings at TSC with a shoulder on them & made some angle brackets to mount the reel assy to the base.
I have over 250 feet of 1/0 cable on them & have never had an issue. I'm going to make one with a 14 pin remote cord on it for my trailblazer. I got a 150' piece of 6 conductor cable that will work good. I'll have to figure out how I'll mount the 14 pin amp connector on the hub though. Maybe a panel mount one will work? Unfortunately, I only have one pic of them, I'll post a few more here soon. Not super hi tech, but they work pretty good. The Reelcraft brand reels with the fancy contact spool on them run about $500-700 a piece. WAAY too pricey for this one man gang. Just a thought anyways. S.W.
I just added some pics, if anyone was wanting to take a look. The reels are a little rusty, but have been on my rig for the last 3 years. Not too bad for an inexpensive alternative to those fancy schmancy ones the real welders use!