This is a show that I've been looking to find on DVD and haven't seen it on TV in ages.

I found the following DVD's for sale:

http://www.classicdvdworld.com/TRAPPER-JOHN-MD-COMPLETE-SERIES_p_120.html

Anyone have any experience with these folks?

Those are Bootleg for sure, T.J has never been legitimately released on DVD.
See: http://www.tvshowsondvd.com/shows/Trapper-John-MD/4358

I have watched quite a few Bootleg DVD's, some are amazingly good, others look like third generation VHS, most are just mediocre.
Most of them were recorded off the air at some point using VHS or Beta, often in edited rerun form all were on burned DVD's.

You pays your money you takes your chances but if you really want to see something sometimes a boot is the only option.

ioffer.com is a mecca for boots, I bought the Batman series there but they were pretty sucky and I never finished watching them.
That show is finally coming out on a legit release his year!