hi guys!!
i just wanted to ask your opinion on what guitar to choose.
The thing is, i only have a very general idea of what kind of sound i want to have, so i would really appreciate an opinion.

I am currently between 3 guitars:
~G&L Legacy
~Gibson SG
~Gibson Les Paul

yes i know thay are very different...

I think that my major influences are Black Sabbath (in the Dio period only), Dio (The guitarist of Dio is Vivian Cambell), little bit of Maiden.

at first i was a big fan of maiden, so i wanted to get a strat, but then i found out that the legacy is far better. But then i really got into Dio (he is my favourite musician) and i loved the sound of the guitar on his solo career (LP). But then the new Black Sabbath (aka Heaven And Hell) released their new album, and i loved the sound of the SG on that one, cuz it's more classic than the LP and heavier, perhaps a little more moody.
Well my guitar teacher (ex-guitar teacher actually) told me:
1. the G&L legacy is certainly better than the strat, but the sound is too classical for my taste.
2. Gibsons are good guitars but if he were me he'd go for a Framus of Godin guitar because they have greater value for the money you pay.

also on Amps, i am between a Marshal, or an ENGL.

ANy opinions an all of these?
if you have any suggestions about other guitars or Amps, it's all appreciated.

I'd say legacy. Maybe a legacy HB for some more versatility.

Classical sound? Strat's are pretty versatile, you can pull off metal with a strat pretty easy. Way better value for money than the gibson.
What's your budget? You can't really say one brand is better than another because each brand makes a variety of instruments. The only way you can find out what's good for you is to try them out. You may end up hating the guitar. Plus, you'll probably be happy tonally with every guitar with humbuckers.
budget is between 1500-1800 euros for the guitar. (i dunno how many dollars that is)
the legacy costs 1500, but i might want to put a floyd rose trem, cuz the legacy has a G&L trem which is better than the original fender strat trem, but i haven't compared it to the floyd rose yet) so it might cost a little more.

now for the amp, i'm not quite sure, so far i have gathered the money for the guitar, but i'm saving up for the amp as we speak, i gues i'll have like 400 in a couple of months, plus what's left from the guitar money. in 3-4 months i'll have around 1000 i guess.
Just to confuse you more...
Black Sabbath - Tony Iommi uses an SG.
Dio - Vivian Campbell played on only the first two albums - Holy Diver was a Les Paul and then on Sacred Heart he switched to the "super-strat" style guitar, a Jackson Soloist.

I think you need to take your amp into the music store and play all 3 guitars through it and see which one gives you the sound you want.