I have mixed feelings about recommending amps to people. They give a list of things they want, but you never know how each want is weighted. So I will give you the ones I feel fall into the category of your wants.
Light weight, under 1000 bucks and 30 to 50 watts.
My first would be the Fender 65 Deluxe reissue. Yes it has only 22 watts but is a big 22 watts and fabulous tone. Reasonably light and good for the blues and classic rock. I take it you are looking for a combo, so my other recomendation is the Marshall JCM 2000 DSL 401. A 40 watt 1/12 with a switchable clean, gain, and high gain channels. Reverb, and reasonaly small package. Awsome tone. I am using it as a head only, through my 2/12 Avatar cab and it sounds great. Try to get one of the later issues because there was a heat problem with the first ones. Also usually under 800 bucks.
The Blues is alright!
Guitars: 1968 Gibson SG, 2005 Gibson SG Standard, 2006 Gibson LP Classic Gold top, 2004 Epiphone Elitist LP Custom, 1996 Gibson Les Paul Standard. 2001 Epiphone Sheraton II, 2007 Epiphone G400.
Fender Strats: 1996 Fender 68 Reissue CIJ, 2008 Squier CV 50s, 2009 Squier CV 50s Tele Butterescotch Blonde
Amps: Blues Junior Special edition Jensen in Brown Tolex with Wheat front, 65 Deluxe Reverb reissue,1970 Sonax reverb by Traynor, Avatar Custom 2/12 Cabinet with Eminence Legend V1216 speakers,
2008 DSL100 Marshall Amp , Fender Super Champ XD,Fender Vibro Champ XD
Effects and Pedals: Fulltone Fulldrive II, Fulltone OCD, Fulltone Mini Deja Vibe, Fulltone Fat Boost, Dunlop Crybaby Wah, Boss DS1, Boss DD20 Giga Delay, Boss TU2 tuner, Boss BD2, Ibanez TS9 Tube screamer, Zoom 505. Radial tonebone hot british.