Hello group

I'm planning to upgrade my computer and have some questions re disk
drives:

I currently using SCSI Ultra-160 drives through an Adaptec 2940 PCI
controller.

It seems SATA easier to find and is less expensive per unit disk space.
Would SATA drives perform as well as the Ultra-160 SCSI drives?

I've been very happy with the speed and reliability of the SCSI drives
though they're only 8 GB. They've been running rock solid for better
than 4 years! So I'd like to stay with SCSI unless there is a compelling
reason not to.

Yet another question: If I could find a motherboard with an on-board
Ultra-160 controller, would this be preferable to a PCI-card controller?

Many thanks