This one from Fluke looks promising
http://us.fluke.com/virtualdemos/28X_demo.asp
The problem with the Sun machines Bear etc. is they are really hard to get parts for.....that being said you can find them for a couple hundred bucks but the early Sun Machines are not small.
http://www.allstates.com/Emissions.html
This is what the 80's had to offer in scope gas analyzer technology