agree with above. The m50 to me are a bit overrated. Theyre not really portable, and to me at least, theyre not too comfortable. The LP2 are extremely bassy. A better solution to me is the vmoda m80. They have a little better resolution and overall a more genre friendly sound signature while still being a bassy headphone. The difference is LP2 = full out bass head headphones vs m80 = bassy headphone.
I could also suggest sennheiser HD 25 ii. The Sennheiser Amperiors, which are the metal versions of the HD 25 ii are actually on sale now and theyre pretty good too (although to me theyre not that comfortable either).
The Soul By Ludacris line is also being discontinued so being sold very significantly cheaper prices. They wont sound as good as the other options mentioned but noteworthy for the price.
As for amping, the only ones that will really benefit from amping is the sennheisers, and even those dont really need all that amping.