Jones plays left midfield as often as left winger. That could e.g. create a 4-3-3 left-side containing Barisic-Jones-Middleton. Not too bad.
Getting him for next to nothing and see whether he can rise to the challenge is a "risk" worth taking. It would not exclude signing one or two creative MF chaps either.
IMHO, Davis on e.g. a 6-months loan (when his contracts runs out) should be on the agenda too. Maybe a look at Dowell of Everton too.
Kamara ... can't tell. We've got Jack and McCrorie for his position, plus Rossiter and Coulibaly. The latter will be off next summer, Kamara's (23) deal with Dundee ends too. So both Jones and Kamara are young and not too expansive ... and, after all, if SG decides they are worth it, who are we to question that?