[CentOS] hw raid 10 with 4 disc, recomended partitiontable

I am familiar with centos and this forum, and have some rhel / centos 
questions. Therefore I'm asking the question here

I am about to install rhel4.5 on a hp dl380 with 4 disc's. The standard 
rhel installation installers all in one partition?
Will there be any advantage of splitting the file system up?
What would be a good recommended partition table for a server running 
scripts handling big amount of transactions?

Normally i would do something like this, but i need to ask the question 
since I haven't installed on a production machine before
/boot
/opt
/usr
/var
/tmp
/home

An other thing, I haven't installed rhel before, only centos and notice 
a difference in that yum is not a part of rhel, and later figuring out 
that no updates are possible since I installed without the graphics's.
Are there other significant differences between CentOS and RHEL?