A good interface is the cornerstone of computer recording. Its the Hub, the Nexus, the ADCs and the DACs, the power and the glory, for ever and ever, barmen.
You can get other devices later, pres and modellers and blah blah, but get a decent interface now and use the lineout of whatever you play guitar into with some impulses (free and easy) while you hunt for monitors (vital), modellers (meh) mics (yay) and better mics (woo hoo!).
Oh, the toneports have nowt on EMU, Presonus, Edirol, maudio Echo, Motu et al.