SeaSterling,  The part number you are looking for is K09CJ for the H310 controller. The cables are 7M80X.  Now a quick note. When upgrading from an S110 to an H310, you CAN NOT migrate the data intact. You would need to backup the data and recreate the arrays. Let me know if this helps. 
Hello,  I want to upgrade an R420 server with the 3.5" hot plug backplane from the S110 raid controller to the H310 controller.  Can anyone point me in the right direction as to where I can order this and what the part IDs are for the controller and SAS cables needed to connect this?  Thanks!
Need to upgrade R420 server with 3.5" backplane from S110 raid controller to 
H310