Thanks for the thread Needed to ask the exact same question.
I just recently(last night) found my old v7 ps2, dusted it off and noticed the network adapter attached to it that I dont remember ever getting after some pondering if I wanted to get back into playing PS2 games but my drive bay only opens half way, I need to pull it out the rest, then I discovered HD Loader and HDA. Now I'm dead set to do it. about to order Swap Magic and work from there to get HDL.
I keep reading that HDL's HDD cap is the old windows 137GB limit!?
Further reading I found that it has bumped up to 300GB in the latest release.
Now Im in the market to look for a HDD thats 300GB or at the least 250GB+.

I have no experience with IDE drives, I have SATA smarts but not IDE.

reading this thread I gather I can ONLY use IDE or eIDE harddrives? EIDE and PATA are the same?
I found a WD IDE ATA-6(also says EIDE) 300GB HDD and a Maxtor PATA 300GB HDD but this one says Ultra-ATA and ATA-7?
work on the PS2?
have to order them, so waiting 1-2 weeks for a mistake is really wasting money.