I see you are using a Reeves? I used to play guitar through an old Hiwatt dr504 so I am familiar with that circuit. I would guess you wouldn't have any problems with getting enough brightness. I have been using a sunn 300T and a GK 700RB with mine and the cab sounds really well balanced and the speakers handle overdrive from the amp well. They seem to be on the more responsive side of things which, in my experience with the Hiwatt, is definitely a plus. I tried a few different speaker set ups with the hiwatt (although we're talking guitar, so bass mileage may not be exact) and found that it seemed to do better with higher wattage speakers with a higher SPL. everything else sounded a little flubby.