ITRemote

To avoid kernel contention, a minimum of four LUNs (Oracle ASM disks) of equal size and performance is recommended for each disk group.

Do you plan to have more than 4 disk groups? 1 TB HDD are usually faster than older 500 GB.

4 Disks Per Diskgroup

Oracle Doc 4 Disks Per Diskgroup

Oracle19c ASM Info

Oracle ASM Limits