If you're looking for really, really affordable solutions you might want to check this out:
THE GOOD: Cheap (60 bucks). Very Solid. Small. Fits 15mm rails. Cheeseplate set up, lots of threaded holes. Has some forward and aft adjustments. Fits DSLR's and smaller cameras like the fs-100/700 and C100/300, AF-100.
THE BAD: No vertical adjustments for rail clamps. Plastic knobs, washers (metal screws, tho). Small/short footprint. Shipped from Hong Kong, so I'm not sure how long it would take to get to you...
I have one, and it's pretty solid. I used it for about a year on my shop's fs-700, and it worked fine. Never stripped any threads, or busted any screws. As for support, well...don't expect any, it costs 60 bucks. the company who makes this also makes a lot of handy little doodads, which you can find in their eBay store, most of which is of middling quality, but extremely affordable.
Here's a version with the vertical rail adjustments: Cheeseplate with Vertical Adjustment
Looks kinda tall, tho...maybe too tall? I don't know. Hope this helps!