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I would seriously look for objective and independent reviews of any such systems. The underlying premise behind battery desulfation isn't exactly BS, but often the actual benefits of systems being sold overpromises - by a significant degree.

@Mark Moussa, I'll second what @kai says above- while the "high frequency pulse to remove sulphation" technique has been shown to hold a certain degree of effectiveness, it's not particularly any more effective than just running a normal desulphation cycle (often called "equalization") and while the process can squeeze a few more cycles out of what would otherwise be a completely dead battery, it will in no way double the life.

FLA chemistry, construction, and failure is more complex than any one product will ever be able to remedy; the problem is not only sulphation, but also degradation of the sponge lead in the negative plates and the lead dioxide of the positive plates, corrosion of the plates, degradation of the acid solution, as well as buildup of sulfide sediment in the bottom of the battery from previous charge cycles (the sulphation, when removed, has nowhere to go but down). Every SLA/FLA battery has a space at the bottom of the case for sediment buildup, but once that space gets full and the sediment reaches the bottoms of the plates, the battery is toast... sulphation or no sulphation.

Bottom line, there are no recommended regeneration suppliers because there is simply no genuine way to bring a dead battery back to life. There are a number of ways to squeeze a few more cycles out of a battery at the end of its service life, but they're all band-aids intended to get the system to work long enough to get you back to civilization where you can replace your batteries. I strongly advise that you don't waste your time or money looking into this markedly snake-oil-reminiscent technology, and instead shift your thinking toward the simple -albeit sad- reality that all batteries (and Pb batteries in particular) have a service life and need to be replaced at the end of it.