Thanks alot for your suggestions. I probably need to go away and do some 
research now as some of those features you spoke about were unknown to me. 
I'm glad I asked on here as i probably wouldn't have thought of many of 
those. 

The memory issue shouldn't be a problem.  It will be in java or php both of 
which have memory limiting features and i can  always add OS level checks to 
processes as a back up.

The other issues i'll need to see if i can disable or restrict in libxsl and 
maybe using app-armour or something as  a back up.


thanks for your help
Andrew