How to lower my ride? Please help a newbie.

[los-lowrider]

Dear all, in the end I ordered the air lift set up. At the moment front is installed and I am more than confident with the result. I think it's real fast and it works great. The options like leak warning are a great help.
I think this took me a big step forward.
System works with 3/8" valves, slam bags, and

WHAT DO YOU THINK???????????????????????????????
Here's the link to a video:
http://www.youtube.com/watch?v=AA7lSpPhuxI

Plans for next weekend are to install the rear bags which will be hard without welding ( without welding because otherwise I am going to get in trouble with the German TÜV). Hope to accomplish this target. In most cases it takes longer than you have thought!
Also I want to lower the rear additionally 2" with lowering blocks, mount a original rear bumber because this should look lower and a tow hitch.

BTW, I use an Range Rover compressor and it works much better than I imagined. Working pressure is 175psi ( which is a lot in my opinion), compressor turns on at 145psi and it only takes 50 seconds from 145 to 175 with an 20 liter tank.