Wich 12" for an open cabinet for Marshall head?

[alfonso]

found a JCM 2000 TSL100 used but mint condition in a shop and tried with the speakers of a "The Twin" amp, (Fender + Eminence)....Great! I had my strat with me (old fender electronics on an allparts alder body and ebony fretboard warmoth) and I was blown away by versatility and tone...GAS took me completely!

I want an open cabinet now and thinking to use a single 12', I need portability (relative...hehe).....suggestions?