The first qn is which port num do you want it to use; you've got 2 different ones there...
The default as per /etc/services is
rquotad 875/tcp # rquota daemon
rquotad 875/udp # rquota daemon
which matches the default setting in /etc/sysconfig/nfs.
Unless you've got a VERY good reason, I'd leave it as that.
If you insist on changing it, make sure you change both(!) files to match.
Assuming you have iptables on, you'll have to amend that to match as well.