Unless you have a specific reason for not wanting an upgrade, I may have a very good reason for you having one - Price!!
The difference between Home and Pro is not readily apparant to the average home user - most of the extra features are specifically for networking, but not a small home network as such. I have both (One on a laptop and pro on the main desktop) and rarely if ever have I noticed a difference.
However, your kids are at school or college/University so if i were to tell you that XP Professional is available to Students, Teachers and Parents at less than £50 would that change your mind?
You can still do a clean installation (in fact it is preferable) and you need either Windows 98 or ME on Disk to "Prove" you are entitled to the upgrade. During the installation you are asked to put the 98 disk in the CD drive, XP looks at it, says "OK, thats a Windows product" and you take it out again - it needs no files whatsoever from the 98 disk. in other words, your "Clean installation" will not be affected by having to install over the top of 98 - Trust me, i have done it many times!
The price? £46.99 INCLUDING VAT