Ive been playing a Marshall TSL 60 Head and a 1960 4X12 cab for years, and came to the conclusion that it just wasin't practical for the small gigs, and jams I was doing. So I sold the rig and did some research on some, great sounding, all-tube combos.
I ended up going with the Marshall 40watt Haze. I have to say, i am really LOVING this amp, and can't figure out why I hadin't heard of it before. Definitley better suited to my needs than my previous rig.
I would even say that I actually PREFER the tone from the haze than the tone I got from my TSL.
Although one thing I must say, is that the sound is a little "boxier", the 1X12 combo defintley lacks the headroom that I got from the 4x12 cab.
Is there any other obvious diffrences between a head and cab vs a combo?
I still love the tone of a head and cab, but since down-sizing was my main issue, I was thinking of getting a head and 1X12 or even 2x12 cab, do you think head room would still be an issue?

The difference here really being comparing an open back combo, to a closed back cabinet... Each have their good and bads to them.... I can see the Haze is ported through the back..... All depends on what you're going for, and speakers can make a difference.... I usually prefer a head myself, as for gigs, you can always rent or borrow a cab, get close to your tones. I've owned combos that shred as well though, and well, comes to what is more practical for your usage. With a combo, it's easier, amp in one hand, guitar in the other. Head and cab, you're lugging around a lot.

Head room shouldn't be an issue with an extension cab, infact, it may give you more, depending on what the cab can handle. Some speakers break up earlier then others. A friend of mine actually used a Carvin X-60 combo for a while for practice, and would drag a Marshall 4x12 with him for gigs, depending on the venue.....

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ESP Eclipse Limited (3/100) or Gibson Les Paul Standard (97) - Fulltone OCD - H.B.E. Detox EQ - Laney GH50L - 80's Ibanez AD-9 (in loop) - Randall XL 4x12
Tortex "The wedge" picks, Blue Steel strings, Line 6 Moble In, Charvel Model 6 modded to a Model 5FX.... Probly other stuff as well

thanks for the feedback!!
Ideally, I would liek to keep the Haze, and get a head and cab rig that is smaller than what I had before.
I was thinking about a JCM 900 50watt with a Marshall 1X12 cab.
What do you think?

Also, when using a cab as small as a 1X12, do I need to be concerned with the amount of juice comming through the cab? I've heard that smaller cabs like a 1x12 or 2x12 sometimes cannot handle large amounts of watts...

I love the 'all in one' factor of combos, but tube rattle drives me nuts, so I try to stick with smaller heads and cabinets whenever possible. Plus, with a low wattage head, you can use a 1x12 at home and then two 1x12's or a 4x12 or two 2x10, etc, etc when you play out.

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I'm just two people short of a threesome.

I'd for sure recommend going 2x12, fuller sound than a one with better headroom. I try to only use a 1x12 at bedroom volumes.

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Talking about wireless pedals...

+1 on cerebro911's comment.

It's always a trade off: convenience for hugeness of sound. I definitely tend to prefer more speakers rather than less. Personally, my favs are 4x10 open back or 2/4x12 closed. I've never heard a 1x12 combo that sounds truly huge. Not to say they don't exist (people say the Lonestar 1x12 achieves that), I just haven't come across one.

In terms of power handling, it's really just a matter of making sure the wattages ar OK, not just the number of speakers. Don't forget that Mesa do Roadstar 1x12 combos and those things are pretty high powered amps. It's not hard to get a 1x12 that'll be fine with a 50 watt amp.

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Crustaceo ergo sum

While I never recommend downsizing from a 4x12 to a 1x12, the haze is a good sounding amp. A 1x12 extension would give you the headroom you need. I build pro guitar cabinets and would be interested in helping you with this Check out RDK Sound Design for some of my work