Digi does not sell any breadboards for development. The following provides some recommendations.
XStream and XCite OEM RF Modules use a standard 2.54mm (0.1) spacing header. Most breadboards have the same 0.1 spacing, so these should be relatively easy to find from any electronic components vendors.
XTend and XBee OEM RF Modules use a standard 2mm (0.079) spacing header. We are not aware of any breadboards that handle the 2mm (0.079) spacing of these OEM RF modules. Some customers have used 2mm spacing prototype boards like the one found at: http://www.engineeringlab.com/throughholepcb.html. However, the problem with boards like these is they require soldering on the radios header pins. There are 2 reasons we would not recommend soldering on our radios:
Our recommendation is to purchase the same type of female headers that we use on our interface boards (see http://www.digi.com/support/kbase/kbaseresultdetl.jsp?id=2018 for details). The leads of the female header can then be soldered to wires that can be pushed into a standard breadboard.
Another option is to use a break-out board to convert the 2mm spacing of
the XBee to the .1 inch pitch of a standard breadboard like this one
from Sparkfun.com. http://www.sparkfun.com/commerce/categories.php
If you have any further questions please do not hesitate to contact Digi Support.