Re: Mini amp head suggestions wanted
This is probably the best suggestion, however, you should consider a Tubemeister 36 or Mini Rectifier. The Tubemeister has a Marshall flavor but not exactly like a Marshall. It has a better clean channel than any channel switching Marshall in my opinion, and it also has a nice reverb which is a nice option to have.
The Mini Rect is a great, great, great little amp. Even though it doesn't sound like a JCM800, it growls, roars and squeals like one. The clean channel (clean & pushed modes) sound incredible, even better than the Tubemeister in my opinion. The vintage overdrive channel has a classic overdrive sound that's aggressive but can be made smoother. The modern channel is very aggressive but also pretty versatile.
I've been able to get a fairly good Marshall flavor out of my Mini Rect by using some Marshall flavored pedals like Catalinbread, HAO, Mad Professor, etc..., but the Tubemeister has an edge on the Marshall thing.
Tubemeisters come with a 1 or 3 year warranty, can't remember, but the Mini Rect comes with a 5 year warranty and is a US company. Both have great power options and great FX loops.
The problem with any low wattage amp is that EL84's are going to sound more congested than the JCM800'ish sound you're looking for. However, if you can get a Marshall 2061x cheap then I highly recommend it. It's handwired and blows away any of the EL84 Marshalls out there. Crank it up and you will have a superb cranked Marshall sound that's not so loud that you will get kicked out of venues. It's a loud 20w, but pretty easily controlled.
Other suggestions could be a Bogner Goldfinger which is pricy but sounds incredibly good and rich with awesome power scaling and built-in reverb. Then Budda amps are also good low-wattage amps with kind of a cross between a Marshall and Dumble flavor or something like that. It's hard to compare the Budda sound but they sound excellent.