I use a Samson Airline Wireless system. It works very well for me, and I don't really notice much of a low end drop off. In fact, it sounds the same to me whether I use cable or the wireless. Best of all it's relatively inexpensive, and very easy to use. The transmitter is a little plug that goes into the bass, and the receiver is like a stomp box with two small antennae sticking out of it. I can run on either batteries or AC, so it's fairly versatile. I use it here in Korea with no problems at all.
If I were to have problems I'd probably try to EQ the lows back in, but again, I've not noticed a problem. Over here I'm using an Ampeg BA210SP combo amp, and it works fine for the places I play here.
Hope this helps,
Alan