Ready for Fish?

Can you measure NO3 (nitrAtes)? When you see nitrItes go down to 0 and nitrAtes go up, that's a surefire way to tell that both types of nitrifying bacteria have moved in and you're done cycling.
Don't quit feeding the bacteria ammonia, they need a source of food, so if you're done cycling but haven't added fish, you want to keep adding some ammonia so the bacteria you worked so hard to establish don't die off.
I believe you'll want to do a pretty hefty water change to eliminate built-up nitrAte levels before you add fish, I think many people do 80% or 90% - you should be able to find more info on finishing up the cycle and adding your fish on the AC site, just look for 'fishless cycling'.

When your ammonia dropped down to 0, did your nitrites also dropped down to 0 within the same timeframe? when both drop to 0 within 24 hrs, your cycle is complete.

Your KH will drop during a fishless cycle. If it drops too much, then the PH can also crash killing off your bacteria. If that happens, you'll basically be starting all over from scratch. I do weekly 50% water changes while I'm fishless cycling and this seems to be enough to keep things from crashing. Has worked for me so far at least.

Your PH is fine at 8.0 as long as it's stable there, so you don't have to worry about getting it lowered or anything. The majority of fish will adapt to any reasonable PH, although some won't breed unless the PH is more to their liking. One of the worst things you can do is add chemicals to raise/lower the PH to an "ideal" level causing it to fluctuate. The PH swings are much, much harder on the fish and can be lethal.

Hang in there, the cycle is almost done now