PSX Resolution Help

[canasniimehugh]

Hello, it's been a while since I've done the whole sprite ripping thing. I want to screenshot rip a psx game but I'm not too sure what resolution I should have the window at. I'm using Retroarch and but it doesn't really give many options for resolution. If no one is familiar with Retroarch then what emulator should I use that will display at native, screen rip friendly resolution?  

Thanks.