You really ought to audition them before making any purchase decision.
They are notoriously (and surprisingly, in regard of their high sensitivity) difficult to drive. They can sound "slow" and "ponderous" with the wrong amp.
Big Tannoys (GRF? I think) were the worst sounding system during the last show I attended here in Brussels. Nasal tonality and the sound was locked in the speaker cone with no openess or real soundstage. Still I'm sure they are great speakers but just aren't easy to set-up and "bring to life". Obviously something was wrong.