2011 SBS Essentials RDP Issue

Hello all, I signed up to EE for this problem.  Recently I had someone build a server for our business.  The reason for new server was we had 15-20 RDP users connecting to our old 2003 server and it wasn't able to handle the load any longer.

We got our shiney new server installed on Monday and after getting everything configured I discovered the hard way that only 2 RDP admin connections were allowed.

This caused major problems with our business.  I have done alot of reading on the subject and realize I would need to purchase the Premium-add on to get the amount of RDP sessions we need.  I have a few questions I hope some experts can help with:

1.  First, would it just be easier to install a completely different Server OS to replace 2011 and purchase the necessary licenses for RDP?

2.  If answer to #1 is no, I realize we will get a license for Win 2008 R2 with PAO which we can install as RDP license server.  Problem is the only other server we have is the old 2003 server but it is very old and i don't know if it can handle 2008.  But if it could, would RDP users be connecting to the old server running 2008 or our new server running 2011 that was build to handle all these users?

I also read I can do some sort of virtualization and install both 2008 and 2011 on the same machine.  Do you think this would be the best solution?  If so, I am still confused after a lot of research what kind of licensing I would need to allow the 20 RDP users.

I could purchase 2011 PAO 20 CAL, but do those 20 CALs allow 20 RDP connections or do I need additional licenses for that as well?

And if I do purchase PAO, how do I actually do that?  Is this something I can just download or do I have to order packaged disks?

I am really in a bind here and need a solution in place to install on Monday, the only day our business is closed.  We have a temporary work around in place for now involving the old server, but that thing as many other issues and won't last long.  Thanks for any advice you can give.