Assuming you intend to use a "flat top" and not a Resonator guitar, pretty much any low end (cheaper) guitar would be fine.

What you need is a high action so that the strings don't touch the fret board as you slide up and down, also heavy gauge strings.

Most cheap guitars satisfy both these conditions.

If you are thinking about buying a resonator then you could try copies made by Ozark, Samick or Vintage for about £300--400.
But these are not that good IMO.