Do you like the tone of your Bandit? The Peavey Envoy has a 10" speaker and is smaller.
Does it have to be a tube amp? The Vox Pathfinder 15R has been getting rave reviews here and elsewhere.
Have you looked at the Spider IV series? I've played on a Spider II, and noticed the same muddiness. That wasn't an issue on the IV I played on recently.
Vox makes the AC4TV head and cabinet that sounds great, at 4 watts. There's a switch on there to reduce power from 4, to 1 watt, and 1/4 watt. Priced at $349.00 USD. Some of the Valvetronix (VT) amps have a switch to reduce power as well.
Blackheart makes the Killer Ant head that is a fraction of a watt in power.
Epiphone makes a "hot rodded" version of the Valve Jr., complete with on board reverb.
Peavey makes the Windsor 20 watt combo that comes with it's own power attenuator.
Marshall has the Class 5, 5 watt combo. It sounds awesome! Price is $399.00 USD.
Good luck!
Guitars:
Fender 2006 MIM Fender Stratocaster HSS in 3TS
Ibanez RG 570 with a bridge Invader
ESP M II Deluxe with a Tune-o-Matic bridge
Eleanor, the magical, mystical Road Worn wonder Tele
Blackstar HT Club 40