Best Database Server and I/O configurations for 2005

We are currently an IBM shop; however, IBM seems to not understand basic I/O configurations with SQL Server and I am pulling my hair one piece at a time.
The particular database in question is a third-party product that is so poorly designed; however, my finance department just think its peachy. I just got about 100K to throw at hardware and licenses so I am going to throw hardware at it. I/O is a huge bottleneck and I am having issues explaining to my network guys that a sql server has to be physically segregated by file type (i.e. data, logs, tempdb, indexes, os, etc...) via seperate controller channels in order to reduce I/O.
Basically, can someone send me some links and suggest an IBM or maybe even a HP 4 way database server with configurations? Maybe what others are using to munch data?

Thanks again!
Bobby

If I/O is your painpoint, then what you want is disk, disks and more disks - enough so that you may be able to spread the pain on enough spindles so that it hopefully goes away. (perhaps a controller or two would also be desirable - it depends somewhat on the # of disks you can get your hands on)
/Kenneth