Although I'm not sure I've ever heard any of his solo stuff, the first thought that crosses my mind is Boris Gardiner. He was co-leader of the Upsetters with Lee "Scratch" Perry but his solo work apparently has a strong Memphis soul influence.
Vampi Soul put out a compilation last year that I've been meaning to pick up:
[img][300:300]http://www.dustygroove.com/images/products/g/gardin_bori_soulfulex_102b.jpg[/img]
dustygroove Wrote:
Wickedly soulful grooves from the Boris Gardiner Experience -- a group that's equally well-suited to playing reggae, soul, rocksteady, and funk! The tracks on the set are pulled from Gardiner's key early 70s sides -- recorded at a time when he was pulling in a lot of influences from American east coast soul and the Memphis scene -- singing like Al Green one minute, playing like Booker T the next, and serving up some excellent tunes that really crossed over into a global soul market. CD features 19 tracks in all -- and titles include sublime covers of "Breezin" and "Melting Pot" -- plus "What's Happening", "Ain't No Sunshine", "Don't Take Away", "Today", "Phoenix", "You Just Got To Be In Love", "Happiness Is A Warm Pussin", and "Let's Stay Together".
Despite the fact that their blurb makes no reggae mention, I note that they still file it under reggae. I'll eventually get around to picking this up and will post thoughts when I do, but feel free to be the guinea pig.
My other suggestions would be to pick up a trojan box set. They have several rocksteady 3 disc boxes that retail for $20 or less each. I have one of them and its pretty great. They also have a "mod reggae" box of jamaican r&b that looks interesting and is similarly priced.
Finally, you might just want to make a trip to dusty groove and ask for recommendations. I've noticed that they've gotten a bunch of rocksteady/old school ska in lately (pioneers, paragons, etc) and a lot of it is priced very cheap.