Thanks all for your very interesting replies!
It does sound as if I might be better with a looper AND a phrase sampler. Presumably they can be controlled using foot switches (my hands are going to be pretty busy!)? Also I'm currently a bit hazy about how they sync to each other.
The other part of me is saying that for the kind of music I do I should keep it ultra-simple and just use the Jamman. I suppose the effect I'm after is of a 'slightly' more sophisticated Seasick Steve, so I'm not looking for multi-layered loops and such like - it's really quite a raw blusey approach - think early Free perhaps. I know that what I should really do is get a decent drummer and bass player, but I'm quite fed up of
the silly ego trips and arguments that inevitably (in my experience) happen in a band situation, and I feel that I'd like to at least give the solo thing a try.
Thanks again.
Rhod