I have two A-frame adapters.
The first one I got from Ballard Fabrication:
Pretty nice unit. Well made, and has the optional tow tab on the opposite side from the sleeve hitch.
The only problem was the tube for the pin. For one reason or another it is under sized, and if you use a pin the fits the tube, the attachment really wobbles around.
To be fair, the fella that owns Ballard is a member over at MTF, and when he saw that I posted about that, he PMed me and offered to replace it, as it shouldn't have come that way. I told him that I was still happy with it, and not to worry as I used it mostly for towing, and that in the mean time I had found a Brinly A-frame that I could use for any sleeve hitch attachments. He definitely has a commitment to having happy customers, and if you don't have the tools/skills to fab your own, I recommend his as it's fairly cheap and will do the job.
As mentioned above, I also have a Brinly HH-1000 A-frame adapter. It's a LOT heavier built than the Ballard, but I think that's really overkill. The down side is that it doesn't have a tow tab like the Ballard one.