Distribution layer design

[colag309]

Hello all!  I'm looking for a little guidance while designing an upgrade to our current network.  Our core layer will utilize two of the Cisco 4532X Catalyst switches routing between networks.  However, our distribution layer will include 6 of the 5406 Procurve switches.  2 switches will be located at three locations, where we access switches connect via fiber.  I'm going to use VSS for the Cisco layer instead of HSRP or VRRP.  As for the distribution, what would be best to implement?  Eventually, each access switch will have one fiber that connects to each of the 2 5406 switches that feed the location.  I have dark fiber between all three of the sites that house the 5406 switches.  We have approximately 28 VLANs that all route through the core.  Right now I'm thinking about setting up trunks between each 5406 and utilizing STP, but I've read several articles regarding virtual switching protocols.  Has someone setup a similiar network and provide feedback?