Putting together my first home media server. Need Advice. (1 Viewer)

So I am building a new house and had the whole thing wired with cat-6 with multiple locations in each room. I want to set up a home media server and have not been able to find as much information as I would have thought. Any advice from anyone who has set one up before would be much appreciated. I will be purchasing a new desktop for the house as all I have are laptops and tablets right now. Any suggestions on anything special it should have? At this point I will have all of my a/v equipment in the office being controlled by ir repeater from the living room. I will have a receiver with all hdmi input/outputs, a ps3 for blu ray and gaming, a wii for gaming, standard comcast hd box with recorder. Alll of this is not problem for me to run. I want to buy a drobo and not have to set up a raid. the backup feature of the drobo is my main attraction after spending all the time ripping dvds to the system. From what I have seen so far PLEX seems to be the software that will work the best to control everything. Other than this I am open to any opinions or suggestions. Money is a concern as the new house is taking most of my funds up to get built so please keep that in mind when responding. Thanks in advance, Paul.

I use a dual drive ZyXel media server for both backing up my PC's and streaming audio and video to a Roku box on my TV. http://www.amazon.com/ZyXEL-NSA320-Network-Attached-Storage/dp/B004UBU3SY Both drives are 2TB Western Digital SATA models configured as 2 drives. I don't like using JBOD since you lose data if either drive fails. I plan on adding a USB drive to this NAS box and use it as a backup of my media files. I spent a LOT of time ripping music. Once I start adding my DVDs & BRs to this server, I will have a lot of time invested in this. If I run out of room, I can even program one ZyXel to FTP files to another ZyXel NAS on my network.