Hi James,
Welcome to Purrs In Our Hearts and good on you for giving the fella a loving home, he's georgous!!. Yo9 will find lots of genuine, friendly and helpful advise on here and I am always so pleasedto hear of someone giving a much-needed loving home to an FIV cat. There are several of us on here that have FIV cats, many with longer experience than me, like Max's "owner" Clare. Yes, you are correct in saying that a cat has FIV for life but there's so much more known about the virus now than ever. I wish you and your handsome fella all the best and we'll all try and answer any questions that you have.
Cheers
Leigh