Mini ITX Server Build and Questions?

[Ovazealous]

Hey guys,
I'm planning on building a Mini ITX Server - to hold a few hard drives and constantly attached onto the network, I was thinking NAS, but I decided on a Mini ITX PC because I can also put the network printing onto it as well as use it for other things.

Here is my build:

Aywun MI-008 mini-ITX Case -
http://www.pccasegear.com/index.php?main_page=product_info&products_id=16778
http://www.aywun.com/ProductDetails.asp?ID=97

ASRock AD2700 ITX Motherboard -
http://www.pccasegear.com/index.php?main_page=product_info&products_id=19195

GSkill 2x2GB RAM SODIMM

And I'll also chuck in a few WD Green Hard Drives - probably start with a 2TB then wait till the price drops again as they are really expensive.
So the total cost is about $150 for the Mini ITX PC without hard drives. What do you think? I want to keep the cost as low as possible.

Questions:
I want to have a least 2 3.5" Hard Drives in the case (while keeping it small)(to justify me building a PC instead of just getting a bigger NAS), from a number of websites - they say that the Aywun MI 008 has 1 internal 3.5" SATA then one external/exposed 3.5" drive bay. What is the difference between ext/int Hard Drive bays?

Are there any reliable large storage hard drive brands that are cheap in this time of expensive hard drives?

 

[o1die]

I'd check craigslist for used hard drives; some of the 250-400 gb drives are less than $50; newegg's cheapest 500gb hitachi drive is around $85 shipped. Newegg or amazon had my ocz agility 3 ssd for $60 after rebate; it works well with my am3 board.