I need to expand (and possibly improve) my current mic setup for two XL2's.

Currently we are using the Sony URX P1 wireless with a single mic in combination with a Sennheiser shotgun mic, both going into the rear XLR's (16 bit), to cover bowhunting expeditions where the guides may be off camera, and the hunters are whispering and may be talking away from camera.
I would like to use the camera mic (to pick up the off camera dialogue), and maybe add another wireless lav on the same frequency, but not sure if I can still get 16bit (the manual is woefully inadequate in this area).
Also, the plastic Sony cases are getting beat up.

My Q's are: Suggestions for more rugged wireless lav's?
Can I still get 16 bit with on camera mic with lav's too?

The Sennheiser Evolution G2 wireless units are fairly rugged....well except for the antennas. I have a few customers that have dropped them and they still work fine. The only complaint I have heard from folks that are really hard on gear is that the antennas break off. They're around $12 so get a couple spares for field replacements. Make sure you get the correct antennas for your frequency (A, B, or C)

As for the XL2 audio, 2 channels only in 16bit mode and 4 channels in 12bit. The on-camera mic takes up two channels (stereo).

For beating around in the bush, you might want to check out the Rover Aux box http://videosmith.com/cgi-local/store/commerce.cgi?product=support&cart_id= to mount the wireless under the camera so the receiver isn't on the hotshoe getting pummelled. A portabrace would be handy too if you don't already have one.

I am going to invest in the Sennheiser set up, thanks for the input.

Jeff

Cool. If you have QuickTime, watch the Sennheiser Wireless Tutorial video via the link below. It'll get you up and running with the unit quickly.

I need to expand (and possibly improve) my current mic setup for two XL2's.

...
I would like to use ... maybe add another wireless lav on the same frequency,

You can't have two wireless mics on the same frequency at the same time because the transmitters with interfere with each other. If you're adding a second wireless to your setup, choose one on a different frequency from what you already are using.