I'm working on a bluetooth chording keyboard using the Broadcom BCM2042. Since the chip is a ball grid array chip, it's quite difficult to put into a prototype. Fortunately, several companies implement Broadcom's 92042 bluetooth keyboard module. Blue Packet is one of them. They sell the 2042 on their BP20422 bluetooth keyboard module (to which I can't link directly, but it's off the drop box.)
Unfortunately, Blue Packet isn't set up to sell small quantities for prototyping. If you send them email, chances are pretty good that you will be ignored. I have arranged to order some modules from them. I am willing to resell them for $30 each, $25 for ten or more, with a detailed data sheet.
The module is very easy to use. It uses a .5mm pin SMT spacing, so it's reasonably easy to hand-solder. You need 9 external parts to turn it on. Five caps, one pull-down resistor, one blue LED + current-limiting resistor, a momentary switch to force bluetooth pairing, plus however you want to supply 3v battery power.
I am stocking these modules, and can accept payment via Paypal. Send email to Russ Nelson. Before you ask, yes, I am still selling these modules.