As someone whose favourite ever game is FF7, I feel pretty well equipped to give you an answer. I've also done what you're trying to do now in that I recently played Suikoden II for the first time this year and enjoyed it alot, despite it being a Psone game I'm playing retrospectively.
For you it's sort of a win-win situation if you play the original FF7. You'll either quickly realize that the game has aged poorly and you'll quit and wait for the remake, or you'll enjoy the original and then probably get the remake also. The only negative in that scenario is that you'll have to buy both games but FF7 is only $15 and is frequently on special for half that.
The main concern is that SquareEnix have not made a great RPG in about a decade (with the exception of DQIX which wasn't made internally). You can just google the phrase "square enix sucks now" and read the amount of threads on that subject. Almost every person who made FF7 is gone from the company and what the remake will end up being will probably be a shell of the original. I know this sounds pretty negative and predictable as obviously I have fond memories of the original, but I am almost certain it will unfold this way based on the rhetoric surrounding the game. Square are also outsourcing the FF7 remake to a studio with a pretty lousy track record. I think you're best off buying the original on sale (the remake won't be out for a very, very long time) and taking your chances. Hey, you might not like it. But you might, and I think it's worth finding out. It could be what Suikoden II was for me. At the very least, the game tells a beautiful story, has beautiful music and great systems. If you like buying weapons, maintaining a party and learning abilities, this game does that masterfully. None of these aspects have aged at all. The only thing that's aged are the character models. Even the environments still look great as they are prerendered.
Fortune favours the bold.
