Data Conversion

I'm in the process of speccing out the hardware for an Oracle 10.2.0.3 server. We're expecting a database in the 200G size. Working set is hard to estimate, but in analagous 100G systems I see a buffer hit ratio or around 70% with a 2.3 G SGA (about as big as I can get it on a 32 bit OS). Based on this and a fair amount of spitball analysis I'd