I don't know if 16" is doable for a CRT... it might be. Best thing to do is go to a store with a tape measure and get a general idea. Alternatively you can go to a number of manufacturers websites will give you the physical dimensions.
An 18" LCD is choice, and definitely great for a narrow depth and the ability to be right up on top of it with excellent clarity. You are looking at spending $800-$900 on a good 18" LCD however, you can get a 17" LCD (much bigger than a 17" CRT which only has a viewable area of 15.8" or so) for around $650.
An excellent 19" CRT is only about $300.