I agree with Moth3r. If you had an amp it would better to use 5.1, so you could have the LFE; but as you don't, stick with 2.0.
If you decide to buy an amp and use 2.0 speakers or headphones, choose which sounds the best. In my experience which sounds better depends on how well your amp or player downmixes to 2.0 and on the mixes themselves.