Ugh I've had issues in the past but it can be done (stupid game tells me my graphics card fails at certain tasks), and it's been ages since I've tried either of them so I'll try to be of help...
IIRC, there are patches online that let them work with modern graphics drivers. Any of the hardware rendering settings that work should do it for you. Software rendering will make you want to shoot yourself. It will also try to install the yamaha synth, which I think works fine and I don't think it bloats up your system.
Also, especially for FF7 but also FF8 I would HIGHLY recommend to rip all the CD's to an image file on your hard drive, and install the game/run the image from daemon tools or equivalent. The videos in game will load up much faster / better.