if you say its a 1000 watt amp... that probably means its really 500 watts RMS... 1000 watts being the peak power... manufacturers always put the peak power on the face of the amp to make it seem more powerful.
What wire gauge are you running now? What kind of amp is it?
For a 500 watt RMS amp i'd recomend 4 gauge with a 80 amp fuse... all the fuse is doing is protecting the wire... if a 4 gauge wire grounds out, it'll blow an 80 amp fuse real quick! A 60 amp fuse may restrict the power flow to the amp a little too much... especially a sub amp that is played loud.
2 and 1 gauge is overkill... nothing thats needed. you only need that stuff when you're running multiple high power amps.