RHEL vs Oracle Linux/Oracle Unbreakable Enterprise Kernel on large x86_64 servers

I need some advise for the following scenario:

One organization is considering to purchase

very large x86_64 servers ( 8-way with more than 1 TB of ram) for running oracle databases.

The current standard is RHEL 5 and 6, tools (RHN-satellite, etc) and procedures are established to maintain and support RHEL. Several hundred RHEL servers are up and running. Also with Oracle databases.

My personal view is that also using RHEL for these new oracle-servers

may be the best choice if at all possible (if RHEL supports the hardware), but oracle unbreakable linux is preferred by others.

The project managers are worried about performance and therefore seems to prefer the oracle offering over RHEL because it has a newer kernel and promises better performance (compared to RHEL5).

Currently it still looks like RHEL6 is not a certified platform for oracle 11g.

RHEL5 is not a good alternative as it does not support such large hardware

(maximum memory supported is only 256GB and 64 logical CPUS. 8-way with 10 core = 160 logical CPUS when hyperthreading is enabled).

So it looks like the Oracle offering is the best choice after all. What do you think? Any pros / cons for both solutions are appreciated.