Daniel,
I am by no means an expert on building homes, much less studios. But I recently have been watching a PBS series called "Building Green." The basic setup of the series is the host is building a home (huge - BTW) in California. Each episode covers building design and techniques and he goes out to various suppliers to highlight different products that are 'green' minded.
Anyhow, he's building a frame place, but it's all going up around bails of straw for the walls. It's pretty cool and amazingly affordable and energy efficient. Looks awesome too. You'd never think this is a straw-built house once it's finished. He shows how you can basically build about any structure with straw and because of how you finish the inside and outside it lasts forever!
I'm just thinking that since you're building from scratch, and cost is an issue, this might be something to seriously consider. It could reduce your cost on wood, insulation, etc. Plus you'd likely have a place that is easier to heat and cool, which would save on energy bills in the long run.
Some links you may find helpful.
| StrawBale.com Straw bale construction | straw bale | straw bale houses | strawbale | straw bale homes Episode Four: Straw Bales | Building Green TV Short video with parts of the TV episode.
This might come from left field, but the show was inspiring to me. I've now been dreaming of the opportunity to do what you're doing now, but make it a straw built house with a rockin' studio!
Good luck and keep us updated in whatever you decide!