Boss GT2? thot it was Boss GT6 and Sansamp GT2...
Sansamps GT2 is a preamp/amp modeller of sorts. not really a multifx.
check out their full range at
http://www.tech21nyc.com
anyways, if you are on a tight budget, then i'd recommend Zoom GFX5 or 8 or if even tighter budget, Behringer X-V-Amp.
If not, you can't go wrong with either Boss GT6 ($715) or 8 (think not out yet), POD XT Live($668), Vox Tonelabs SE ($729), T.C Electronics G-Force ($900 plus). but TC's rack unit does not have distortion la.
dunno about yamaha's stuff, never tried it but reviews did not put them in good light.
for a huge array of reviews on almost every imainable guitar product, try
http://www.harmony-central.com
also, depends on your needs. do you need usb/optical/midi ins and outs etc? best for you to check each unit's individual specs if you have a particular need for a function like for recording or something. hope this helps.
oh btw, welcome to the guitar world!