I haven't seen any 2012's in the refurb store but I see that BandH has the i7 2012 2.3 server in stock for $899. How is the server different from the "normal" mac mini. I see that it has 2 1TB HD's. I'm assuming I could just upgrade it to an SSD and 16 GB RAM myself and use the 1 TB HD for backups. What displays would you recommend to go along with the mini. I think the current apple display is overpriced. If this can lasts me about 3 years + I'll be happy.
Yes, you could use it that way. You don't need to run the server software on it, just re-install OS X with Cmd-R at bootup - it's the same machine, of course. You could also run one or both HDDs (e.g. in RAID 0) if you like. With 16GB performance is fine (I have single 1TB drive 2.3 model I set up last week - with 4GB it was frustrating, but with 16GB it's quite nice).
Of course, an SSD is even a bit better, and can be configured as a Fusion drive or left separate. The Samsung 500GB (and especially 1TB) 850 EVO are very good values, as it's a reliable brand and the price/performance is quite good, with the 1TB nearly matching the 1TB Samsung 850 Pro's performance for ~$250 less. At these prices you can afford to over-provision about 12-25% of the drive (I'd usually do around 18-20%) and get great capacity and performance for the $, and generally be fine without any TRIM support (since you can't securely get TRIM under OS X Yosemite with
any third-party drives - the alternative being finding a used Apple drive on eBay or somewhere).
As for displays, I have two 20" IPS Dells I plan to continue to use, so I haven't looked into displays extensively for my own use lately. But a relative's just broke, and the Dell u2412M and u2415 look pretty good, as well as the "factory calibrated" ASUS PA248Q. All of these have the preferable 16:10 aspect ratio (my 20" Dells are the old 4:3 ratio, which I especially like).
Saving a little money isn't such a bad idea, since you may need to put some $ toward a photo storage and backup solution as well, if you'll have over 1TB of photos and don't already have that figured out.