not sure about running the Vandersteen with a low wattage tube amp, the 2 minimum recommendation is around 40 watts...so hearing it before buying with your power amp is probably a good idea....also the corner placement might do some strange things with the rear facing acoustic coupler...you are likely to get a lot of room gain and a lot of bass.....IF you wanted to stay in the Vandersteen line you might consider the VLR and a sub which you can adjust output on.
iF you like Vandersteen also check out Theil and Dunlavy
iF you like Vandersteen also check out Theil and Dunlavy