Windows Small Business Server 2003 – Raid Choice?

I am setting up my first file/printer server using SBS 2003.

I have a HP ML370 G4 Proliant server with:
2x 36 Gig drives
6x 74 Gig drives

Controller = Smart Array 6400 SCSI

What Raid path would you take and partition/volume sizes with the above given drives?

OS partition
App partition
Data partition

Also my box has 8gig ram, SBS max is 4gig so now what? Pull 4gig?

Thanks for any recommendations!

-mellow