Suggestions for small covert cctv unit

We have had some "issues" with consumables going missing on a site and I have been asked to look at setting up an IP video camera in the area.

The requirements are:

1. Wireless network connectivity and the ability to push recordings to a share/NAS
2. Water-resistant
3. Battery powered with approx 2 weeks life
4. IR/Night mode
5. Small enough to be reasonably covert
6. Motion triggering

I honestly dont know if all these requirements can be reasonably met.

I have found this unit (http://www.swann.com/s/products/view/?product=1423) which seems to meet all requirements apart from the network connectivity - It saves to an SD card instead.

I could probably live with local recording if needs be but I thought I would throw it out here in case anyone had a suggestion.

Any ideas?