ultimate collection free month + returning playersFollow

hi guys

LONG time since i been around here XD

sorry if this is covered already but i had a look in stickies and searched but couldnt find what im looking for.

im looking at maybe coming back to FFXI but im missing some content (scars and heroes of abyssea)

if i buy the ultimate collection from steam (£9) - can i add those missing pieces to my existing collection?

also, can i make use of the free months subscription on my existing account as this would justify buying it entirely!

thanks guys!