The SRV-tone can achieved with many different guitars, amps, pedals and speakers as long as you use them correctly together.
But, after having said this – SRV hung on to some specific pieces of gear and ways to use his gear, that made his tone as we know it. Strings It is not just the matter of big strings, it’s the relation between string gauge and the power in your hands and fingers. He had no problems with bending and shaking 013, 015, 019 strings for hours.
Tall and large frets will make it easier for you to bend and shake, since your fingertips are raised from the fretboard and thus reducing friction.
Also make sure that the neck wood and lacquer is smooth and not braking and limiting your bend moves when in contact with your fingers.
A guitar set up for SRV is not easy to master for entry-level players that favor easy-played low-action guitars with thin strings.
A valid question is if the audience can tell if you have a small or big amp when they hear the guitar and amp through a PA? You can nail the SRV tone with small Fender amps too.
You deserve to try playing Mary had a little lamb with a slightly cranked Princeton Reverb equipped with a Jensen C12n speaker. Just make sure the amps are dialed in correctly with powerful speakers that don’t distort and have lots of punch, both lows and highs. Make sure it is not pushed too hard into distortion, but set nicely at its sweet spot with just s little power amp breakup (think Little Wing intro).