Hey Pix,
So you are talking about a fairly small studio room then? I'm doing a 10X16 with a separate control booth, starting the soundproofing in the framing by using 6X header and footers, and staggering the 2X4 studs to the surfaces so that the drywall on each side don't share a common stud. Fiberglass "woven" through that and acoustic foam on the interior surfaces. Carpet on the floor and acoustic tile above. The tough issue is HVAC, did a lot of brainstorming with a buddy who was a contractor and has lots of experience dealing with ventilating tight spaces (like server closets). He recommended high volume low speed ventilation for both heat and cooling.... ducting substantially oversized and additional baffles on the discharge and returns. Mostly concerned with sound and getting heat out of the confined space. After an hour shut up in a booth, it can resemble more of a sauna than a work space, and any electrical equipment trapped in there with you just gets too uncomfortable.
I have two concerns that I have to deal with, sound abatement for the comfort of my neighbors, and a "clean" environment for myself and clients. A larger area for group instrumentals, and a booth for individual vocals and acoustic instruments. I gathered up a bunch of soundboard panels (surplus cubicle walls) that I intend to convert into mobile partitions to help dampen any transient echo in the big room, and as needed can do double duty as barriers to any doors and windows. Speaking of doors, you might as well plan on building your own, as anything pre-fabbed will not have any kind of sound deadening between the skins.
Electrically, another thing to consider is "power conditioning" a good sized UPS should do the trick to keep the electrons flowing at a constant rate. Protect your equipment!
Take Care;
Doug