I just verified on a system with a B120i. hpvsa-1.2.44-4.rhel6u3.x86_64.dd loads fine with Centos 6.3. Are you sure your using 6.3 and not a different release version?
All I did was gunzip the image and copied it to a USB stick. On the kernel boot line, I added "blacklist=ahci dd" The blacklist option isn't required for a B320i controller, just he B120i
During boot, the installer asked if I hada a driver disk, then pointed to the usb device and loaded the driver