Hey Halo's are universally praised as great amps. I bought a Marsh Sound Design A400S based solely on positive reviews and have never regretted it and this was after home auditioning nearly a half dozen power amps.
I'm sure the problems I heard are related to break-in and setup. I'll go back in a month or two and re-audition. The buzz on these speakers is just too good.
The Focal should be a great sub. It looked very imposing at Tweeter. If you'd like something a little smaller with great performance consider a Martin Logan Depth for about $1800. That's what I have and am very happy with it. Three aluminum cone 7" drivers arrayed on every other face of a hexagonal cabinet. Very compact and very powerful.