mrdecibel, amp first approach is only if you just really want to use particular amp or preamp/amp, normally it's either speakers or source first, of course. As for the room, well, yeah, unless you move frequently.
jl35, that's a good point. In fact, I was thinking of upgrading speakers first soon but couldn't resist getting VAC amp when I saw it. So now it's amp first and speakers later for me.