I am with TJHUB and kshep. I would, however, get room treatments right away, or at the same time you get the preamp and/or DAC. Get those suckers in place so when listen to a new piece of gear you'll fully hear what it has to offer. If you wait till till the end concerning the room treatments, the sound might change again, making you realize you no longer like the preamp, DAC or amps.
Room treatments are very important and are often recommended as an immediate thing to purchase, but oddly enough most people wait till the end.
That's just my $0.02, and YMMV.