Assuming you're using an emulator with a plug-in interface, which GPU are you using? If it's Lewpy's, you have to turn "Experimental Screen Flipping" on. You'd probably get other opinions if you were to post in your emulator's particular forum.
>what drivers should i use for epsxe?
I'm assuming you're wondering what plugins to use. What kind of video card do you have? If it's anything by 3dfx use Lewpy's Glide, Geforce-based cards should be used with Pete's D3D or Glide GPUs. Though I've only seen a few postings about Radeons, most people seem to use Pete's also. The mileage you get with another card can vary greatly. If you haven't any of the above see what kinds of details you can gather and ask the board about it.
PS> If you really *were* asking about drivers, I'd suggest using whatever the latest are from your hardware's manufacturer.
Why not post your system specs and the plugins you're using, if you are using ePSXe. If not, then the recommended emulator to play FF 9 US NTSC version is ePSXe. It can be got from the download page of www.psxemu.com Then you should check out all the FAQs which are located at psxemu.com You can also get the plugins necessary to run the games here as well. After you have got the emulator, read the FAQs, and got some plugins, if you are still having problems, then as I said, post your sytem specs and the plugins that you are using. Then we will be able to help you better.
VGS is a fine program, but you need a patch to run FF 9 on it. You can find the patch and any others you may require, at www.aldostools.com Also keep in mind that VGS will play FF 9 as if it were on an actual PSX at 320x240 resolution. Where ePSXe, using the graphics plugins, plays it at a much higher resolution giving, in my opinion, a much more enhanced and enjoyable game to play.
>when I start battles, it gets a bit slow
It's like that for most people, so it's not really something to get stressed over
>How can I turnthe CD into iso? I don't have cd burner.
You don't really need one, as a normal CD-Rom drive will work just fine. You need an ISO Dumping utility like Isobuster or a general purpose program like CDRWin or BlindRead/Write.