I went with a ThinkServer TS140 (Passmark Score 7017). 3 1080p transcode streams on Plex.

http://www.amazon.com/gp/product/B00FE2G79C?keywords=thinkserver%20ts140&qid=1448996100&ref_=sr_1_2&sr=8-2

1 x ThinkServer TS140 = $345.49 1 x 16GB USB Drive = $17.48 3 x 4GB ECC Ram = $104.61 2 x 4TB WD Red Drive = $317.38

Total = $784.96