Have they asked for anything specific at all ? Vinyl, wood, rubber are all suitable really, aren`t they My choice would prob be an acoustic vinyl. Nice soft feel to it, and some quite nice ranges. Or how about a click lvt. We just did a gym, and I was impressed with the way it looked.
http://www.gerflor.co.uk/solutions-for-professionals/product-page/creation-clic-system,257.html This is what I fitted, there are a few available.
something like a sports floor junckers maybe, although a clic lvt onto a good subfloor would be easy maintenance and quick as hell to fit
A mate of mine was looking into this recently and taking professional advice from dance instructors. Apparently the ideal scenario is wood fitted over joists. The reason being the spring in the joists is far gentler on the joints.
ive just done a gym. carpet tiles in main area, a rubber floor for the free eights area then a wood floor by boen for the studio. Id be surprised if your client hasnt asked for a proper floor for high impact areas like the studion.