Pick a shortlist of 5 or 6 DAWs, download the demos, and try one per night, for a week - or two weeks, even. I know the feeling of just wanting to pick something so you can get on with learning and making, but. My only other advice would be - DO try them out. This way, you get a piece of hardware you'll need sooner or later, and a useful version of a popular DAW to try out at your leisure, and keep for later. If you buy a Native Instruments controller or interface, it'll come with Native Instruments stuff.
The MOTU interface I just bought comes with a version of Digital Performer that is, from what I can tell, not very limited at all (I haven't installed it yet cos I've got enough DAWs to be getting on with!) Most come with a limited version of Ableton Live, some with a limited version of Cubase. Don't forget the option of buying a physical thing: if you buy a keyboard controller (you'll need one) or an audio interface (you'll probably need one) - it will come with free software.
