Which version Omen are you looking for? There are 4 models to choose from:
1- Omen 6 (the basic one)
2- Omen 6 FR (1st one with a floyd rose trem)
3- Omen Extreme 6 (a heavily modified version of the 1st one with better PU, fretboard and stylish fretboard art and a completely different body construction)
4- Omen Extreme 6 FR (3rd one with a floyd rose trem)
Now If you are talking about the 1st and the 2nd one one (which I think you are because the Omen and the Omen FR and the Epiphone SG belong to the same price range), you have two guitars with a heck of a difference to choose from... You will probably, need a tremolo bar for playing psychedelic rock, heavy and progressive metal, therefore the 2nd and the 4th Omen are your only choice as the SG isn't equipped with one...
SG vs Omen 6 FR
-SG's got 22 frets while the Omen's got 24 so the former would be great for progressive soloing..
-SG has a mahogany body, which is warmer sounding and is great for blues, hard rock and soft rock though can adapt really well for metal.. Omen has a basswood body, definitely the pick for most metal players... Mahogany and basswood are very different sounding...
-SG has a handsome ebony fretboard uniform and with great access and good action... The Omen 6 and Omen 6 FR's fretboards are among the ugliest ones I've seen... They have a high action and really thick necks, are not at all recommended for players with small fingers.. However, this is not the problem with the Omen Extreme 6's, whose fretboards don't have those issues...
-The pickups of the Omen 6 are specially made to handle metal well... Nice and ariculate, neat and clear for sweep and legato runs... Though they sound crap with blues... And crap meaning real crap... SG pups are less articulate, less clear, dirtier and more harmonicky.. I've never tried an Omen extreme though I have a hunch that it will be a lot better than the SG's...
-Last but not the least comes the tremolo bar and the bridge... The Omen 6 and the SG doesn't have one but the Omen 6 FR has a floyd rose original.. The Omen 6 has a TOM string thru body and the SG has a TOM stopbar bridge (better than string thru, easier to replace strings, no holes in your guitar :P)...
So choose the better one as per ur preferences... I suggest you go to a store and play the guitars and choose the better one...
You should try out these guitars also, great and within ur price range:
-Greg Bennett Torino TR3
-Greg Bennett Avion AV3
All I wanted was a gun.... And they handed me a guitar instead....
- Samick Greg Bennett Avion AV3 modded w/ Seymour Duncan Full Shred Neck (N) and Duncan Distortion Bridge (B)
- Blackstar HT5C
- Boss CS3
- Digitech Bad Monkey
- Boss ME 70