Need advice/opinion in choosing Vandy 2ci or Thiel 1.5

I have to agree with @Holmz re: the Vandersteens 2’s unfussy compatibility with various amps. One of the most accommodating speakers I know of in that regard. Though I do have a particular fondness for PSE, McCormack and Audio Research with them.

2jjss49, I’ve heard this criticism across various Thiels including larger models from time to time. My experience suggests that this might be more to do with the sloping baffle and ceiling reflections. When I moved from an 8’ ceiling to one with a 15’ peak the soundstage with the very same system including Thiel CS 2 speakers (soon after changed) expanded quite a bit vertically. A bit of room treatment could go a long was to mitigating what you’ve described. FYI, Most Thiel's and Vanderseens are designed to be listened to at standard seating positions, (which interestingly varies by only a few inches for almost everyone) at a minimum distance of 8' for time alignment driver integration. 

@holmz, I don’t swap gear in and out all that often, especially speakers. I’ve kept speakers for decades. What usually causes such changes; is a change in rooms. The room / speaker relationship can not be under emphasized. And this is Audiogon, changes are not that difficult.
@audiomax, For what little it’s worth; I didn’t much care for Thiel’s earlier 1 series, but the 1.5’s and later 1.6’s are to my ears much better, and favorites of mine for small rooms. I should point out that both the Thiel’s even more so for the Vandy’s, need proper room setup more so than some others to perform their best. Small rooms often offer less flexibility in this regard. Both brands offer co-axial designs that are much more forgiving of compromised room set up. Again for what little it’s worth; as much as I think the Vandy 2’s just might be the best overall value in the history of audio, I’ve never much cared for Vandersteen’s 1 series. I firmly believe that one should buy amps for speakers, not speakers for amps. With that said, your current proposed amp will probably work somewhat better with the Vandy 1’s than the Thiel CS 1.5’s.

While this might not be his forever room, this might not be his forever system either.

While I ultimately much prefer the Vandy 2’s to the Vandy1’s, @audionoobie is spot on regarding the Vandy 2’s being too big for such a small room.

There's still support available for Thiel Audio loudspeakers:

Coherent Source Service – Specializing in repair and restoration of THIEL Loudspeakers

The Vandy 2’s are more room sensitive, the Thiel 1.5’s more amplifier sensitive. These Vandy’s have deeper, but less articulate bass response. Other than that it’s just a matter of personal preference.