I know you are looking for a CRT, but I'd like to suggest an alternative anyway. Have you considered LCD screens with extremely good interpolation quality? For example, the Dell 2709W is very good in that aspect. Will allow you to play games at lower resolutions and in a 4:3 ratio if needed. By not running at the native resolution you will lose some sharpness obviously, but good interpolation will really help and since LCDs are already much sharper than CRTs, it's not that much of an issue.