Dyanco Mk III's speaker suggestions

My first venture into tube gear is a pair of Dynaco Mk III's that I will be using with a McIntosh C-28 pre-amp, Sytemdek TT and Onkyo CD player.

I've done some research regarding speaker compatibility with tube amps and understand that a higher, mostly flat impedance curve is important.

I am interested in full range speakers that would not require the addition of subwoofer (although I have an Outlaw LFM-1 I can use if necessary).

My music tastes are all over the place from hard driving heavy hitting rock (Opeth) to mellow (Cowboy Junkies) and everything in between.

My budget is ~$1500 and I am OK with well cared for quality used speakers.

What would you recommend I look for/audition/consider?

Thanks in advance.
Get something that is nominally 8 ohms (especially in the bass!) and has an efficiency of at least 91 db. That will take better advantage of the amp's abilities.
Don't know if you're into vintage speaks but I run my Acoustic Research AR-90s with my MK3s.