I have a pair of Zu Soul Superflys and can vouch for their efficiency as well as their great sound at both high and low sound levels.
I use low powered valve amps, a vintage Luxman SS amp as well as a Peachtree iNova at various times and they all work very well with the Zu's.
Whilst I haven't heard the Klipsch Forte line I can say that the Klipschorns will also suit you but the WAF might be their Achilles Heel.
Good luck!