In What Order Do I Make A New Account?

Right then.. You will have to excuse the brain fart here. But it's been a long time since I started a new account.

I currently own two accounts. Linked to one SE account.
And am wanting to start a third. Yes I know. I'm mad. Tell me about it :p

So... my first question would be. Where would people suggest to get a registration code from?
I bought a registration code already from Steam to finish off my first accounts Abyssea packs + obtain that juicy hat.
It would never let me buy another copy of the game for my second account so I used Amazon I believe. To finish off that Abyssea content etc. also.

I logged into SEAMS and noticed under [Services and Options] > [Select Service] there is a [Add a service account] button.

So, assuming that I had a registration code from wherever.. Hell I'll buy a retail copy from ebay just for the code if need be.
If I enter it into that location will I be all set? As in, will I then have an account that I can log into FFXI with on one of my comps and start creating characters? If indeed I've paid for some from the SEAMS first naturally. Which I suspect will be the easy bit in all this..

TL?DR?
Will someone come round my house and sort this out for me? I'm getting old and confused lol.
I'll provide tea + biscuits.

Buy the PC download off Amazon. You'll get a registration code without having to DL anything. Then, yes, you would enter that code using the 'Add a service account' button.

GIMME BISCUIT

Hipster not included

If you're not in a huge rush, you could also wait for the ToA collection to come out alongside the expansion in a couple weeks(ish).

That's actually my big plan in all of this.
I'm assuming that there will be certain 3 person minimum content in the new pack. So am preparing myself to do it solo. Because that's how I roll.

Would also allow me to do even more of the old content even easier.
Again, not saying 99% of it is actually hard solo at the minute with 99 cap. But easier is better.

To be Frank (and I am) I'm not seeing a PC download for sale on Amazon. The only link I'm getting for the Ultimate Collection is sending me off site to 'Gamesplanet'

Now I'm not that averse to creating an account with this site or anything. They take Paypal which suits me just fine.
But will they make the code as easily accessible without forcing me to download the game or anything is what I want to know?

Can't remember how it went from last time I bought it off Amazon.
Steam I know you just click the 'CD Key' in your Steam library under FFXI.

Edit - Ah I'll just go for it. It's only £17.99 anyway.
I could take the hit lol

I'm in ^^
First time I'll ever play a Mithra except as mules.

That is my plan next week hehe having 3rd opens up lots more options for me to do stuff since my LS exploded/friends quit game.