4th hard drive in Dell Dimension XPS gen1

I would like to add a 400 gb IDE hard drive to my Dell Dimension XPS gen 1 (big blue tower type case) or the gamer PC. I already have 2 HDs attached to the internal IDE and a 3rd HD attached to a Maxtor ATA 133 PCI IDE controller card. The power supply is 450 watts so power should not be a problem.

There are only 3 internal enclosures in the hard drive cage containing my current IDE drives. There is room in the case for an additional smaller cage.

Is their a spare cage to attach to the current cage that could handle 1 or 2 3.5 inch IDE HDs? I would also need spare power connections that could y or branch off my current power supply cables.

I would appreciate any ideas on how to do this and where (website, etc..) to purchase any described parts.

Thanks,

Steve