Pro/E runs well on Athlon chips. I havent had a pentium since the original Pentium 200MHz! The Athlon chips are cheaper and as yet I have had no difficulties. I am using Win2k Pro with a 1.3 GHz Athlon.
I've seen Pro/E run on Durons, Celerons, Cirus, and other less fortunant processors. I would say go for it....The XP chip is supposed to be really good. My guess is that Pro/E would be smokin on an XP chip (of course its not all about the processor).
Krh-proe I scanned the article you referenced and I have to say that it is a little dated. All XP's and MP's have a thermal protection diode now, thunderbirds do not. At the time Hot Spot - How Modern Processors Cope With Heat Emergencies was written there were no motherboards / chpsets capable of utilizing the diode. Now most new motherboards are able to throttle or shut down the system in the event of an overheat occurence, at least Asus and MSI boards anyway.
I personally run the A7M266-d, (with dual 1900+ MP's), and it is supposed to be able to fully utilize the diode and shut the system down in the event of an overheat, however, I am unwilling to verify for you.
Also, I take the optimistic view. If my CPU'(S) fry in a year I have a good excuse to upgrade.
Yes, I do own stock in AMD, but I also own stock in Intel as well.
Athlon xp is fine, just check the (essential) on-motherboard cpu temp monitor (should always be happy if its below 60)whilst giving the cpu a hard time. This will verify that the cpu selection is now not the main dilemma, the case is. It should be aluminium with sensible cable routing to help airflow and dissipation unless you can afford to specify a chiller.