I would say try Tracktion2, it has a very intuitive and simple interface, and it still has got all the function of the more established recording tools. Is relatively cheap too.
Amp modeling plugins?
Guitar Rig from Native Instruments for example is a fine piece of software, sounding no worse than any other modeling amp out there and even comes with its own controller board.
The big plus is - you can easily do re-amping, e.g. record your tune once and then change amps and stuff afterwards.
A modeling amp like POD (XT, LIVE....) or V-AMP offers more flexibility if you also want to use it without a computer, e.g. into the return of your
combo amp, or practicing just using the modeler and headphones...
Really a matter of taste and what you´re about to do.
Hope that helped.
Cheers,
Carsten