Yeah, a SF Super is a sweet amp!
Wattage is dependant on Make/Model as many makers exaggerate while others are modest in how they report the wattage.
i.e. 18 Watt Budda Twinmaster is LOUD, and will hang with just about any drummer, and a larger band.
30 Watt Peavey Classic, not as loud.
*No dig on the Peavey here, as I REALLY like them. This is just to point out the wattage ratings aspect.
So, you need to determine if you want the amp to be clean at high volumes, or "cleanish" with some grit. Also, there are ways of using your guitar's volume controls and a nice Boost Pedal to get a lot of tonal variety.
Sounds like you may know a few other guitarists in your area? Maybe they will let you come to their practice(s) and try their amps out? Or, let you sit in for a tune or two, to check them out?
Also, go listen to the best bands around, and pay attention. Between sets, the guitarists who sound the best to you, will probably be glad to tell you what they play, and why. Most players are friendly. Especially if you slather them with praise! "Oh Man! YOU are sooo awesome! What kind of amp is that?" 
And one thing I'd consider is Reverb. Do you really want it? I find that Reverb can make your sound indistinct and get you lost in the mix, when playing in larger rooms. I much prefer a slight Echo, myself.
But, that is just preference, I suppose. I would definately explore what the better sounding playes in your area are using, and how they are using it. How is probably more important.
Reverb? Okay, does it need to be built into the amp? I've heard a tiny little Alesis MicroVerb sound incredible through an effects loop.
Yeah, I dig vintage Fender Verb. But, Digital Verb is also something I love. Different, but not lesser IMO.
I find many players (I have done this myself, in the past) long for a certain piece of "Vintage" gear, only to finally get it and realize it only does 1 thing. It may be a great thing. But, it can quickly be so limiting that you find yourself spending lots of time, energy and $$$ trying to get it to do more. Mods, extra Pedals, new PUs, etc. On and on.
Again, go listen to at least 5 or 6 of the most popular bands you can, that play similar musics. Ask a lot of questions! You'll probably find a lot of helpful players out there.
And lastly, if you play with a P.A., you can use a smaller amp and a good Microphone to run it through the P.A. Lots of wattage isn't necessarily preferred either.
One of my favorite amps, is a Torres PrinceTone, Jr. Supposedly 20 Watts, but no where near as loud as the 18 Watt Budda. Sounds great though. And with a Mic in front of it, it can handle as big a room as it will ever need to. Killer Reverb too! 
P.S.
Budda also used to make a Verbmaster amp. Like my Twinmaster, but with Reverb. Not in production any more. But, you can find them for under a Grand used. And they are built like tanks! No reliability problems there.
HTH
Early 80's 1957 U.S. Vintage Reissue Stratocaster (Surf Green)-Warmouth Soloist Pearly Gates Neck, Pearly Gates Bridge- Larrivee D-03 (Mahogany/ Spruce)
Carmen Ghia Head- Marshall 112 Cab W/G12H 30 or Custom 4 X 6v6 Head or Budda Twinmaster Plus Head-Traynor 212 Cab w/Eminence Texas Heats.
Mo'D-Eternity-Blues Pro- Timmy-BYOC Chorus/Vibrato- TC SCF- Korg DT 10 Pedal Tuner
