HPUX 11i means 11.11
HpUX 11iv2 means 11.23
HP doesnt ship anyother OS versions atleast in this region.
HP has a solution builder called SBW, in which when you design the solution like hardware type, number of HBAs, NIC, internal hdd, you have the option to specify the OS version too, there you have two options - 11.11
& 11.23.
11.11 is vxvm 3.5
later releases of 11.23 is 4.1
As far as patches are concerned, you have standard patch bundles and you have specific patches that your application demands, which can be downloaded individually.
Standard patches are also called support plus which contains Quality Pack, Feature Pack and Hardware Enablement Patches.
When you buy the HBA cards from HP, they have a list of parts which is supported in 11.11 and 11.23. All the HBAs which are supported in 11.11 may not be supported in 11.23 and vice versa. The driver for these HP authorized parts are bundled into the OS. Any driver upgrades are generally coupled with support plus patches which are released time to time till the OS is supported. HBAs from another manufacturer who claims would work under 11i or 11iv2 comes with a driver CD.
Hope this helps.
Kind regards...Avi