http://www.techedge.com.au/vehicle/wbo2/default.htm

This is the OZ-DIY-WB site where you can get a preassembled Wideband O2 monitor. Looks like cost for assembled kit w/ cables and digital indicator is about $250 w/ another $250 required for Honda NKT sensor. They're working on another version utilizing a BMW Bosch sensor but I don't know yet if this is any cheaper than Honda's unit, and WB setup for this is not yet available.

My current dream (gonna have to wait til budget allows) is to install the dual EGT indicator from Pegasus to show carb balance, then the DIY-WB indicator on the common exhaust pipe. The 6 cyl Z exhaust manifold lends itself to this as it has a 6-2-1 pipe arrangement. On a multi carb setup w/ headers, an approach would be to port one cyl exh pipe for the WB analyzer then rejet all carb barrels similar. It'd facilitate carb jetting w/o dyno.

Later,
Al