Dual Terror is great for what you want.
The Line6 DT 25 is not bad either, less character then the Oranges, but quite versatile and convincing tones.
Btw, 18 watts is usually enough for small gigs, but it depends whether the is amp is miked trough the pa. At small gigs I use sometimes a Blues Junior thru a 2x12cab (for more bass/mids). The drivesound comes from an Emma Reezafratzitz, the solosound from a Suhr Riot-pedal. Works very well.