Smart Array P400 (bootup issues)

Ive had the question of 'upgrading/replcement' options of an array, preff without having to fair RAID fallout.

im planning to replace these 800's on SMART error notice with 1tb's from SeaGate.

but can i do this without having to struggle much about errors, no posts ect ect.

AND ive also the weird error in the '3rd' raid array that the 5th disc is dying so thats why im asking this.

the drive gives this error not frequently, and only from time to time when booting the system, that has been running now for 4 years.

the server, and the P400 have the latest firmware installed.

I run the following config:

HP DL185G5, thus 12drive's

1. 2x WD Raptor, 300gb RAID1
2. 1x WD Green, 800gb JBOD
3. 3x WD Green, 800gb RAID5
4. 3x WD Green, 800gb RAID5
5. 3x WD Green, 800gb RAIID5

if you need more info, plz let me know, and i provide