The 302USB says it can run (at least to me without checking further) power off of USB, does not say recording via USB. That would have to be checked. The 302 Behringer also has no MIDI port.
 
The second one (Focusrite) is only 2 analog inputs, it has no MIDI port either if you need one.
 
The third one - Audiophile 48 kHz resolution for professional audio quality - implies that it records up to sample rate 48kHz - no MIDI port.
 
The choice is yours, but wording in advertisements (or features) may have to be checked on any such unit you buy to make sure you are getting a unit you want. (that may mean also going to a local music store to view the unit and all of that). With on-line buying places, make sure the unit has and does what you want it to.
 
Otherwise I already bought my unit, so again the choice of what you get is up to you.
I like stereo inputs for - effects (usually effects are stereo while some may be used mono).
 

Something to consider if you go down the Laptop route, is if it had a DVD drive, you can later swap this out for an SSD drive (you'll need a caddy). SO instead of investing in a 7200 rpm drive to replace the 5400, a second SSD will spread the load and be faster. Of course you can later change the 5400 as well.
 
32bit windows only allows 4gb of ranm then can't use it all, so aim for 64bit if you are looking for 8gb of ram or more. You'll see the specs in my signature, this has so far been fine. But having shifted slightly towards more sample based (XLN Addictive keys and drums) it's starting to strain. I am looking at the Hewitt Packard Envy series, but these are the only higher spec option in the country I live in. I have seen some positive feedback from forum members with this range of laptops, who are generally Aussies, which is not so far from me.

spacealf
The 302USB says it can run (at least to me without checking further) power off of USB, does not say recording via USB. That would have to be checked. The 302 Behringer also has no MIDI port.
 
 

behringer mixers with USB ARE soundcards/audio interfaces.
however, since I can't find specs on it (even on behringer's website) I suspect that this is a 16bit DAC and probably uses the USB Codec for drivers.  I never recommend a 16bit interface for anyone doing recording.  24bit is easily obtainable and yields much better results.