Multihome with public and private address

Hi all, I am new to linux and wondered if anyone knew about the
following.

I would like to host a server which has a public IP address to server
a website - also I would like this machine to have a private IP
address to server my home network. I know I shouldn;t do this for the
security purposes but have limited funds for mulitple servers etc.

This machine runs Redhat 9 and has only one NIC. I can configure the
NIC to have two IP's eth0:0 and eth0:1 but would it work with two
differing IP's. Also, can I configure the firewall (iptables via
firewall builder) to protect the external IP packets to only allow
port 80 and 443 but not to restrict the internal IP?

Or do I need two physical NIC's?

AK