Choosing a Hardware/OS Platform for Informix.

Here's my situation. I have to install Informix (Dynamic Server) on a machine, and connect it (probably via ODBC) to another server and the internet. My question is, should the database reside on the same NT server as the web site? Another NT server? Or possible an HP 9000 running HP/UX? My preference is for HP/UX, but I'm having a little trouble justifying the additional cost to management and the customer. Here are the systems we are looking at, all servers will have plenty of RAM, and probably a 90 GB RAID Array. The system will be used primarily for reporting. HP LH III (2 Intel PII 400 MHz, NT 4.0) HP LXr 8000 (4 Intel Xeon 400 MHz) HP K380 (4 HP PA 240 MHz) Sun/Solaris would be an option, but the customer site were looking at is biased towards HP.