Two thoughts.
Universal players often need a screen to navigate to different formats on the disc and for 2 channel listening offer little benefit sound quality wise. Personally I would look for a simpler source option, probably computer based if I possible, given your work, you probably have plenty of computing power and the knowledge required to integrate music playing into your system.
You may already have a collection of music on different media and may, for example, need a blu-ray player for your work, or be working towards a fully fledged multi-channel A/V setup, in which case the point is moot.
Secondly you have a smallish square room, a lot of very good speakers are simply not going to work that well unless positioned optimally, probably difficult in what is also a work environment.
At the risk of once again upsetting the forum, active speakers offer a genuine advantage in terms of control in the bass region and could be a very good solution should they have to be placed in a position that is less than optimum. Active loudspeakers are relatively rare in the hi-fi world, though models are available from the likes of Kef, Dynavector, AVI and others.
Active speakers are much more common in the area of multimedia and music prodution, a line that is particularly suited both to this and domestic use would be the Adam Artist range, though they are quite hard to find.
BTW. Your Sennheiser 'phones are seriously capable, you should make sure your system either has a good amplifier for them or provision to add one, very worthwhile if they are going to be used a lot.