For a Les Paul kinda tone, you should try your E.Q. settings, get a new distortion pedal or amplifier, which are doable. You can't get a true Les Paul tone but you can sound pretty close since the SA260 has a mahogany body (if I remember correctly).
If you want it to sound exactly like a Les Paul with the increased sustain, you're going to need a set-neck, but your SA260 has a bolt-on neck, so I doubt you can get an exact Les Paul tone from it. It is essentially a humbucker-equipped stratocaster, so you can fat tone but with twang and a little less sustain.