Looking to purchase a used bass boat, and was told the year of the boat was a 1999 and the model was a 185 for a Stratos.  However I can't find that as a valid model in the NADA.  Anyone have any ideas?

Stratos did make a 185, not sure about in 99 but if that's what they said, then probably so. If it's the 185 J, that meant it was on the Javelin Hull. A lot of people prefered the J models because the Javelin hull was a faster hull than the Stratos hull. The 185 was more of their entry level boat without all the options, trim and some of the features of the 285.  

Not sure what year they cut them back from 175 to 150 max hp, but with the 175 they made a nice fishing platform.  They do ok with a 150 but those extra 25 ponies made a big difference.  My 285 Pro actually has more storage room than the Javelin R20.  When I started moving everything from the 285 to the Javelin, it wouldn't all fit in the Javelin.

The year of manufacturing will be in the series of numbers on the starboard side of the transom.  They should either be molded into the fiberglass or on a plate.