You may already know about this, but www.thegearpage.net is probably the hugest website totally dedicated to all things guitar gear. It can be a harmful place to spend too much time, but in moderation it can really help you get an idea of what sounds good out there. There are some guys on there that have million dollar rigs, no joke. I don't let it put me down, I mean who really needs 15 Two-Rocks, 10 Divided by 13's, 8 Fuchs', 6 Mad Professors, etc. Just take everything with a grain of salt on gear forums because there is a LOT of bias in each post. I'm as guilty as any but I definately don't put anyone else's stuff down. As you mentioned you have a Marshall MG, there is a demo on YouTube of Rob Math (Marshall rep) playing one...holy friggin' cow. Just goes to show you, tone is definately achieved by practice and hard work even on cheaper amps/guitars. Good luck, and thanks again!
-Justin
'67 and '74 Fender Twin Reverbs, '74 Marshall 1987 lead mkII, Metro Superlead 100. Pedals from TC Electronic, Ibanez, Dunlop, BK Butler, Electro-Harmonix, Fulltone, Maestro/Gibson, Loopmaster switching, VoodooLab, Boss. Gibson and Fender guitars, Dimarzio pickups.