Scalable hardware solution for Hyper-V

Hello, 
I need to install a server 2012 r2 with Hyper-V and was looking for a scalable hardware solution to launch my VM. 
I've never had the opportunity to install a blade server, my question is the server blade has a single operating system and resources are seen globally or each node has its own operating system?

I was thinking of using blade servers Super Micro, but support tells me that I need to install on each node Windows 2012, because the nodes are independent.

I have to start about 30 VM, HW solution which you think might be possible?

Thanks in advance

Fabio