Upgrade Order - SPP or OS First?

I have a ProLiant DL380P-G8 system running VMware 5.1.

I have two sets of updates that need to be applied.

1. The most recent HP firmware updates from the SPP disk.

2. The VMware 5.1_u2 updates from the HP specific update disk.

Both are "boot from DVD" updates.

Question - Which update should I do first?

Bonus Question (if you're feeling generous) - Why?

Thanks all in advance for any time and insight.

JC