I would try out Cubase VST, depending on your soundcard you should be able to plug your guitar straight into your pc and record directly into the sequencer. It also comes with a basic version of WaveLab which is pretty useful for editing. Unlike Guitartrax you can write any amount of midi accompaniments into Cubase and if your system is powerful enough you can have infinite tracks of audio and midi. If you like this, then you can splash out on Cubase SX or you could always have a look on Bearshare or Morpheus for a cracker copy... not that I would of course!
I have heard that ProTools is better/more versatile for professional audio but Cubase VST has more than enough for a basic home setup and it won't break the bank.