Just depends how close you want to get IMO - there was a thread about getting Warren's SLO tones on a Mark series Mesa.
I'd like to check out that thread but can't find it?
Hmm, it was several weeks ago, not even sure why I remember it (I didn't post), but I'll do a quick search and see if I can find it. Now I'm wondering if it was about Warren at all, or just coping a SLO lead with a Mesa Mark series amp... Either way, it came out as expected: people who were big SLO fans said no, you can't get the same tones, other people said you can get close enough and the SLO is based off the Mesa MK series.
I don't know much about Warren or Jimi's gear - I like them both a lot, but I'm not a Marshall fan and never played a SLO, but I figured I'd mention the Mesa thing in case OP is looking for SLO tones as an MKIII might be the most cost effective way to get kinda close (liberally speaking).
I appreciate you searching for me! I love Warren but like most, he sounds like himself through whatever he plays. To my ears he sets up his SLOs to sound like a goosed Marshall so any good goosed Marshall can do the Warren thing. Esp with an H&K Roto.