Endura is much thinner.
Though if you want something for office carry the smaller Delica would work better.
However, have you looked at the Spyderco Squeak? Small, thin, light, no lock but it's not needed, low ride clip, good steel.
Another good Spyderco Slipit to look at would be the Urban - Good steel, solid, comes in friendly colors(Orange especially), very light at only 2oz, thin, low ride clip.
The Spyderco Air however is the ultimate gentleman's/office knife in my opinion. Beautiful silver twill scales, light weight, milled titanium liners, liner lock, M4 blade steel, slides right into the pocket, not even noticeable that it's there, weighs 1.27oz and can handle all kinds of work.
That would be my pick if I had the money. If not, the Squeak is cheaper than the Endura and Native. The Urban is just a little more and has nice G-10 handles over FRN.