I hope you are not specifically looking for an 840*bt*, (as in a model 840*sbt* but without the serrations), because there is no such thing as a plain edged, BT-coated Ascent/Eclipse in any size.
(**Sigh**)
Yeah, it ticks me off too, because they have been advertising on their site that they had the plain edge BT coated Eclipses out before they even introduced them to the market a really long time ago!!! I brought it to their attention long after the knife was introduced and I had noticed that there were no plain edge BT coated Eclipses to be found, and they said "Oops, did we write that?". I see that they have not taken the time to take that false claim off their site, and neither have they made the darn knife for us. (*grumble*)
Many of us have been trying to get Benchmade to make an 840bt, (or better yet an 830bt and 820bt) for quite some time. Many of us hate serrations, and would rather have the blade all serrated or not serrated, but we hate the nasty hybrid Jack-of-all-trades-master-of-none combo-edge. Ug!
Maybe you can bug Benchmade yourself a bit and try to talk them into making them. They have been receptive to the idea lately, but slow about it.
Ps- I would suggest that you handle the 840sbt before you buy one, it is a beast, and I was immediatly turned off by it. Big and clunky. JMHO, YMMV.
ciao,
thaddeus