[Hampshire] Adding a new system disk

My old eide system disk is now 90% full, so I have invested in a larger one,
also eide as I am using the sata ports for a raid 1 array and did not want to
get involved with the complications of booting off raid.

So I have a some questions:

1. Should my new big, faster disk be made primary master, with partitons
on /dev/hda1 etc, or will the system be just as fast with the disk as primary
slave (/dev/hdb1 etc) and the old disk (used as backup) staying as primary
master?

2. If I do make the change, will the present system still boot correctly if I
tell the bios to boot from /dev/hdb? If not, is there a way around the
problem without moving the disks around more than once?

Thanks for any help. This sounds like a standard howto question - but I do
not remember seeing one.

David Webb.