If you want 'blues' out of yer Marshall, gotta be JTM45 all the way - they just have the voicing for it. the Bluesbreaker combo is the same amp but with tremolo added.
I personally prefer 4x12s so I'd go with a JTM45. I also had a Bluesbreaker for a while that I used with an old Marshall 2x12 - that was a 'best of both worlds' rig :D
Alternatively, I think old Selmer amps slay ANY reissue Marshall - these are what I used after the Bluesbreaker rig since the Selmer was very similar but had a punchier tone with more harmonic complexity. Best bit is that you can pick them up on ebay for £150 all day. They're point-to-point wired and totally bomb-proof. Spend another £50-£100 and get a revalve and cap-job for a solid gigging amp.
:twisted: