+1 on the python. I used to do water changes like you do with the gravel vac and 5g buckets. I swear the python is worth it, you can even get extensions so no matter how far away your sink is from your tank, you should be able to do it. It is well worth it, especially for a 60gal.
When u gravel vac do you stir the gravel/sand? If so, don't; try to keep the stirring to a minimum. So for a deep gravel vac just push the vac into the gravel and wiggle a bit then lift and repeat for the next section. The nice thing about the python is that it has a lot more suction power than just a gravel vac (which works based on gravity, this is why you need to keep the level of the water going out below the level of the water going in and why unless you fill the tube with water as was suggested, you need to suck on one end then immediately lower the output end below the level of the input to get the syphon going). I digressed........python having more suction power will not only help do your PWC faster but also there will be less debris floating around since more of it gets sucked in. I agree with everyone else that you have a lot less hassle with a python.
Regarding your substrate, there is something called a substrate flattener, I haven't tried it myself but don't see why it shouldn't work, here's a link to one they sell on ebay so you can see what it looks like:
Aquascaping Tools - Substrate Flattener ADA style - eBay (item 260651088700 end time Dec-13-10 05:33:53 PST)
Hope this helps