I doubt FF 7 or 8 will come on GOG. Recently I saw FF VII in the video game store (where they sell old games too) and it was 50 euro's.

Not knowing that FF7 came out for the PC makes me feel really old, and I bought my first PC in 1998 (same year the game came out).

I also own both FF7+FF8 for PC!

Although if GOG ever wanted to bring them here it would be easier to emulate the PS versions.

Not sure if having Square-Enix here is enough to get them though, would GOG require permission from Sony as well?

I have the PC box copy of FF7 and FF8 back then. Favourite one still is FF6

Yeah, FF7 and 8 came out on PC but I must warn you: if you wanna buy (and more importantly find) a copy you'll probably pay quite a sum. Since it isn't a gem of a conversion and also a JRPG, a genre not so appreciated among PC gamers, I recommend you to wait GOG. Or find the "Greatest Hit" version for PS, but it's still a more expensive option than buying from GOG anyway.
Just think about if you are more a player or a collector...

I bought both FF7 and FF8 for PC for full price when they were new, which was quite rare for me even back then.

After I had completed both maybe two or three years later, they apparently had become special collector's items, and I got considerably more money for both when I sold them away second-hand.

While PC versions may have had some weaknesses compared to the PS1 originals, in my sales pitch I remembered to mention what made the PC versions special compared to the console versions:

- PC version of FF7 included some (silly) chocobo minigame that the western PS1 version was lacking (IIRC), only available to the Japanese PS1 version, if you had some extra accessory for your Japanese console. EDIT: I googled it, and I guess the minigame was "Chocobo World" for Sony Pocketstation, which was the accessory. Hmm, google says it came with FF8, not FF7, so I might remember wrong...

- PC version of FF8 had higher resolution FMV than the console version.

I think those also helped me to get some FF fans interested in the PC versions, even if in other areas the PC versions might have been lacking.