PTAC / motel room air conditioners

Hi All- New to the forum after having lurked + read postings for a long while, and am now in the final (hopefully) stages of "the plan" to convert a small backyard workshop into a rehearsal (primary) and recording (secondary) facility. Interior dimensions (stud-to-stud) are 9.5 x 14.5, and 9-10' from floor to underside of roof. Will supply more details as I pose more questions related to walls, ceiling, floor, etc. Hoping to accomplish this on a budget of approx $5K. As is well-known to folks in this forum, AC is going to be a challenge (compunded by the heat here in Austin, TX). Have looked into mini-splits, and all three AC contractors have quoted me approx $2800 installed for the heat-pump version, plus an additional $500 or so to build an inlet/outlet pair of ducts to supply fresh air. Don't like this for a couple reasons... obviously cost, plus the additional holes in the wall required for air exchange. One HVAC contractor has raised to possibility of something known as a PTAC (Packaged Terminal Air Conditioner)? These are the types that you commonly find in hotel rooms. See here: http://www.lodgingac.carrier.com/detail ... 48,00.html http://www.commercial.carrier.com/comme ... 85,00.html About $1,500 installed (maybe less) for the heat-pump version, which does bring in air from the outside, and also has a backup heater for the rare winter days when it drops below freezing. Of course... it would require a big old hole in the wall, about twice the width of a standard wall-mount AC unit. PTACs are apparently mounted in a sleeve, which can apparently be sealed pretty well, but of course the sound leakage out of the bldg (my primary concern due to proximity of neighbors) would likely be compromised. Question is... how much? Given my limited budget, relatively limited objective (I'm primarily shooting for a rehearsal facility, with fairly limited hours of use as work & family take up most free time, also I'm not opposed to 'turning it down')... I'm already planning for "good" sound isolation, but it doesn't necessarily need to be absolutely bullet-proof :). So... am thinking more along the lines of one of these things as opposed to a full-out mini-split that would be quieter inside and out, but considerably more expensive. Any thoughts? Or...any ways to either (i) find a cheaper mini-split alternative, or even (ii) find a decent way to make a (good) window-mounted AC/heat pump work? Thanks! Greg Austin, TX