Ralph

I had about the same situation with a Room about 18 X 26.
I went with a Master Portable Dance floor as it has its own spring built into it and that way I can remove if I ever move. While it cost more then installing a hardwood floor it provided better options in the long run.
It cost about $10 per square foot at the time I bought it compared to around $4:00 per square foot for hardwood.
Based on your room size you could do a Maple plywood floor for fairly reasonable $