Sun or HP server for Informix ODS ?

Hi all. We need some advice, as we are considering buying a new server. Sorry in advance if I forget any key info, as I am newbie in buying systems this size. It will run Informix ODS v 7.?, supporting about 90-100 users, with about 15 of them running very high CPU-demanding applications. We have several databases, not very big though (about 0.5 gyg each one). All out applications are running in the server (Informix 4GL RDS), though in a future we will port them to C/S (maybe using PowerBuilder). We are considering mainly two systems: - 2 x 300 MHz CPU Sun Ultra Enterprise 3000 - 2 CPU HP 9000 K260. Storage will be 4 x 4 gyg + 4 extra disks for mirroring. Memory : we think 512 Meg will be OK, but suggestions welcome The system should be easily upgradable as it is possible that number of users will increase substantially. Any coments on good or bad experiences will be welcome. Plse, also e-mail me to (xavi_cheto@redestb.es) Thks in advance. Xavi Cheto