Hi Don ... yes a GREAT report on performance in your link.
Firstly .... in my opinion for a server - do not buy a cheap server ... In perspective, buy affordable quality hardware, and maybe sacrafice a little speed for additional memory if money is tight. Cheap components will eventually lead to a catastrophic failure at some stage.
This next point is a personal preferance, but has got me out of trouble on several occastions. Where I don't have a failover system as a backup, I always use a good quality Intel RAID card and attach a backplane with at least 4 drives. (a cheap backplane is OK here). The Operating system is on one pair of drives and Mirrored (RAID 1) and the applications and data are on the second pair of drives (RAID 1 minimum). If you have 6 drives available, then a RAID 5 could be used for applications and data. I also use where I can in smaller organisations single processor servers.
Why .... rationale ... RAID for when you have a drive failure and if you are at all technically minded and follow the news groups, you will know that hard drives have a high rate of failure, irrespective of the quality you buy, and generally high use drives in like a data centre last between 2-3 years. Look at some of the reports on the Google Data Centre failed hard drive replacement stats. Always have at least one spare close at hand. As for drive selction now, I use SATA2 as a economic compromise on performance vrs cost. The seperate RAID card, well if a motherboard fails, I can lift the lot form one system and scavange another system to plug it into as a temporary measure in maintaining up-time. Hence the same rationale for using a single processor system .... the always have one aroround, how many have a spare dual processor system lying around? With Windows operating system environments, that is an important as the OS install is different for single and dual processor configurations and not compatible with each other (an important recovery consideration and implication)
As for the rest ... itn is pretty well covered in Don's setup.