Edit: I think I may have misunderstood the OP's actual intent here. As @joojaa has commented, looks like the OP wants to apply circular end markers. This can be done in the Fill and Stroke panel: Stroke style, Markers drop down. I'll just leave the rest of my answer here as it directly answers the question about snapping options.
There's no option to snap to end nodes only. Inkscape already has a lot of snapping options, far more than any other vector editor I have ever used, and I can't think of any others that have such an option either. If you still want this, I suppose you could make a feature request.
Anyway, there are a couple of other possibilities I can think of, but I don't really know if they're any more "satisfactory" than what you are currently doing. You can be the judge.
- Enable Nodes snapping and Cusp Nodes snapping, and deselect all the other node snapping options, then zoom in close to the nodes you want to snap, and move the path until it snaps. This is a very simple solution IMHO.
Or
- With Nodes and Cusp Nodes snapping enabled, also switch on snapping to Other Points: Object Rotation Centres. Click twice on an object to bring up the rotation handles, and click and drag the Rotation Centre to snap it to an end node. Repeat for another object. Then switch off all Nodes snapping, and finally move one of the paths. The Rotation Centres will snap
An example showing the Object Rotation Centre snapping method