I can’t understand why we’re talking about some holy war of technologies.
You post some information about Mysql 4 and SqlServer 2000. Both products are old versions.
Please, read about Mysql 5.0 and the latest vesrion, 5.1.
Second, there isn’t any techonologie better than one, it depends about your request.
And finally: do you want to use Magento?. Magento runs on Mysql.