I will certainly checkout the extreme processor availability you mention on EBay later on
In terms of the drives I use, currently I have 2 x 2TB Samsung spinpoint drives in the 2 available bays which have been very reliable and quiet, shame they seem to have been killed by Seagate since the buyout
I am running SSD's in all my other PC's, of particular note was the latest purchase a Corsair performance pro 256GB drive which sits in my main laptop - very fast but I think this has even been superseded by a new generation now - things are moving pretty fast in this market
I would be very interested in people's thoughts on using an SSD in a pure media centre machine as capacity seems more important than performance on the drive side of things. Although I think I saw someone comment that they had put an ssd above the DVD drive and said it just fits in ths case, so that might be a good way of getting an ssd in without sacrificing the capacity of a traditional drive?
I have tried to avoid the external approach as it is in the lounge and I don't (well my wife doesn't want) technology everywhere. The only external item I have is a bare drive docking station so i can back up my data and off site it to my parents (I can't stand the thought of having to re-apply all the metadata to my music and movies!!!)