I'm fairly certain your motherboard has a 133MHz FSB setting. That leaves you wide open for the PIII -EB series. If not, the -E series are still considerably better performing than the Celeron. Based on my testing I estimate the PIII 850 will outperform a Celeron 1.1GHz slightly, but a PIII 800EB (that's the 133MHz FSB version) will do about the same. So if your able to get the 133MHz FSB, the 800EB, 866, 933, and 1000EB are your best choices.
What's the frequency, Kenneth?