Server setup

I am setting up a new server and have a question. This server has 
three 8GB SCSIs, and one 160 GB IDE. I was interested in striping the 
SCSIs, which I have done. After installing FreeBSD 7 on the IDE, I set 
up the stripe and moved /var over to it. 

So, my first question would be whether I should put /var on the stripe 
or /usr ? 
My next question might be whether it was even worth striping the 
SCSI's and just installing, say, /var/log to one drive, /usr/home to 
another, etc....
Final question, assuming I go ahead with putting /var on the SCSI's, 
how do I now recover the partition that was being used by /var? 
There's about 3 Gb on there. 
Perhaps I could just mount it as /usr/ports? or should I choose a 
different approach?

Thanks for any input.

OH! BTW. This is going to be a backup server using BackupPC, so I will 
be installing an additional IDE later.