Procurve 2910al series redundant paths

[ASEBP]

I am managing an environment that is spread out over multiple floors.  Each floor has multiple Procurve 2910 al series switches that are stacked and are daisy chained together using the 10-GbE al interconnect kits (single port 10Gb expansion modules).  The stack is connected back to the Procurve 6600ml core switch with a single Fibre optic link from the Commander in the stack.

Obviously this is a bit of a problem from a redundancy standpoint as there are multiple points of failure with having only a single link back to the core and having only 1 core switch, but in addition to this, if ANY switch in the stack goes down, all switches that are connected below it also lose connectivity back to the core.

What I would like to do is add an additional Procurve 6600 to the Core and then add an additional link back to the new core from the bottom switch in the stack so that I have multiple paths from each stack back to the core.  I just want to know if this is going to work the way in am invisioning.  

It is probably worth noting that I have spanning tree on for all switches on the network so this shouldn't introduce any network loops.  If i do go ahead with this change, should i set the spanning tree priority of the new link to be lower than the existing link, or should it work without this?

I have included a diagram of how things are currently set up and a diagram of how i want things set up.  If there is any additional info needed please ask.