Well,
after much messin', swearin', and pulling of hair I decided to ditch the countless tutorials and apply a little intuition.
RedHat may have not compiled the RPM with PHP but surely it can't be that hard right?
First I re-installed the system as a custom install making sure to choose the webserver pakages and SQL (i think it just installs postgre) etc to make sure my messin' hadn't ruined the default setup.
Then I installed MySQL in this order
mysql
devel
client
server
(I dont have the exact names in front of me)
from the RPMS dir on disk 2
rpm -Uvh package.rpm (dont just click 'em)
Then you can install the php-mysql-****
from the same place in the same way and all will be groovey.
I've done this from memory as I'm in Win currently and as to a novice as that's what I am.
I hope it helps so please let me know!
Best of luck
Nick