Hi! First of all, welcome to the photography world.
Given the fact that you have just started to buy photography equipment seriously, I would suggest that you do a bit of homework prior to the purchase.
First thing first, you are comparing the Nikon D70s vs Canon 20D - an entry level camera vs a semi-pro, so it's not a good comparsion.
COMEX is selling the 20D with kit lens for $2,969, with FREE Battery Grip (BG-E3) + Lens Book. I believe that you can get better price at some of the store, like Alan Photo, MS Color or TK Photo, you don't have to buy at COMEX. If you ever need help to buy the body, do feel free to contact me, I can accompany you to buy if I am free on that day.
Back to your comparison, based on features and functionalities of the 2, you have to decide for yourself which one suits your needs and budget.
Major advantages of Canon 20D over D70s
1) Magnesium Alloy Body - for Outstanding Durability
2) 9 point AF - faster focusing
3) 8.2 Megapixel CMOS Sensor w/ DIGIC II Image Processor - high resolution for cropping
4) 5 fps - for capturing fast actions and sports
5) Batter Grip, BG-E3 - additional batteries, better hand holding
6) Mirror Lock-up via Custom function - minimise camera shake esp for Macro or Night photography
Major advantages of D70s over 20D
1) Half the price of 20D
2) Solid 18-70mm kit lens
3) Flash X-sync speed of 1/500
4) 2" LCD monitor
5) Spot metering
6) Light weight
7) Focusing Screen - On-demand grid lines which helps in framing/composition