Hi,

I'm a guitarist too, here's what I would suggest:

use headphones to record your guitar sounds and turn off your external speakers and any other equipment you don't use to reduce interference & hum when you're recording

As you have a strat - standard single coil pickups are inherently noisier than humbuckers (premium modern single coils are sold as noiseless however). Make sure your guitar has shielding inside to reduce noise. Also roll the volume and tone pots back on the strat, that might reduce noise too

use quality leads between your guitar and digitech, and digitech to PC

experiment with gain and volume settings on the digitech and pc soundcard input mixer. You might find that a little less gain on the digitech reduces signal noise alot. If you don't get this right, your recordings will still sound distorted regardless of how much you spend on soundcards

To answer your specific question on 'great' sound quality...

Get a decent soundcard, inboard or outboard. You will find the separation of instruments and depth of sounds is amazing compared to a standard card. I have an EMU 0404 outboard - lots of inputs & outputs, mixing of signals etc and the clarity of sound is impressive

Get the best monitor speakers you can, they will bring out the best in your music. Monitor speakers are designed to faithfully reproduce the recorded sounds i.e. there is no coloration that you can get with hifi speakers. I have Tapco monitors by Mackie and again, they sound fantastic

Once you have a decent soundcard, don't forget your headphones may need upgrading. And always use quality cables to hook everything up!

hope this helps

regards,

Martin