Definitely get a cheap caliper and do the measurements, if you have a buddy to measure the parts you can't reach yourself I recommend the Jackson/Pollock 7 site measurement method. You may find, as I did when I first got my caliper, it is easy to be consistent, but it is also easy to get a wide range of values from a specific area. I would pay to get tested bodbod/hydrostatic once, and then use your calipers on the same day to do your measurements, in this way you will be able to "calibrate" yourself on taking the caliper measurements, so you know you are doing it right. If you can do it again the next day and get the same measurements, you should be getting pretty accurate numbers each time you measure with the calipers in the future!
by the way, you and I are around the same size, (well, youre a little taller...), If you get the caliper I would be interested to know some of your measurements / lean body mass calculation. don't get me wrong, i'm not look for a "I'm bigger than you" contest here, its just interesting when you find someone with a similar body type as you to compare against... anywho, just a thought