Yeah I feel you. Often I’d be the same way; a lot of the time I end up picking original games over remakes because of how they change the look and tone. I haven’t gotten around to Suikoden yet, but I saw some screenshot comparisons the other day of the remaster that just came out and they messed it up so badly 
It’s a bit of a compromise on my end but I’m running on a 4k monitor and 800x600 is the tiniest little square on a portion of my screen, while blowing it up is just gonna blur the game to hell. In the end I think what I’ve seen of the remake art is still nice despite losing some of the unique look the original has, and I’ll be able to focus and kinda immerse better with it full screen and etc. It is a shame they couldn’t just get high resolution versions of the original art, but maybe those never existed in the first place.
I still think the backgrounds are nice and look relatively similar based on what I’ve seen, but honestly I don’t recall the later game ones you’re mentioning super well because I originally read this 8+ years ago now. My memory has slipped about a lot of it; I’m excited to see it again 