Upgrading from 4.6 to View 5

I'm interested in upgrading my environment but trying to determine if its best to upgrade to ESXI 5 first and which hosts should be upgrade first.

Here's a sample of my topology

ESXI1 & ESXI2 (running ESXI 4.1 U1) are in a cluster and being managed by vCenter1.  On these hosts are my View Connection servers and a VM  vCenter2(this is the vCenter instance that manages View and has the View Composer piece installed)

ESXI3 & ESXI4 (running ESXI 4.1 U1) are in a cluster and being managed by vCenter2. Only virtual desktops are located on these hosts.

I guess my questions are....prior to upgrading to View 5, can I and/or should I upgrade ESXI3 and ESXI4 to ESXI5, or should ESXI1 and ESXI2 be upgrade first since the View Connection server and vCenter is installed on them?

My other thought was just skipping the ESXI 5.0 upgrade and just upgrade the View pieces.

Any thoughts or advice?

Thanks,

Mike