I am certainly not as network savvy as some of the IT gods on this site, but here is something else that you may want to consider (and IT gods, please correct me if I have been misinformed):
I am told that wireless networks are considerably slower than standard ethernet connections (as slow as 11 mbps, I'm told). As a salesman, I have always shyed away from adding any wireless interface because the clients perception is going to be that my MFP is slow and not their network (and a color MFP is going to make this even worse due to the larger file sizes).
If your client currently has no network at all, you may find it easier to sell them an inexpensive hub and simply create a small network for them eliminating all of the wireless issues that you will probably have to deal with (and it would probably be cheaper than the $300+ they paid for the Bluetooth Interface).
Just a thought and like I said...please correct me if I'm wrong!