I also use the Thule racks only because that is what I already had from
some previous vehicles.  My van has those little rack thingys installed on
the poptop (and a good idea is to put little electric part rubber/plastic
boots on the exposed screws to minimize chafing on the tent material).  The
Thule hardware fit perfectly like it was made for it.  Yakima is a good
brand, seems to be more popular these days than Thule in my neck of the
woods for some reason.  I used the large clamps which raised the rack
enought to open the vent nearly all the way, an issue if it were lower.  I
put 3 longboards with covers on my rack and with some muscle was able to
hoist the roof up with little problem.  Bringing down I closed all windows
to use the ballooning effect which worked marvelously (save one little
problem where I stressed the material as it got in the way of the clasp).
These boards were way heavy, one of them being a relatively thick 10'6".
Your relatively light ski stuff should pose no issue.  I live in SoCal so
there are a host of stores that have either system available for immediate
purchase that in a matter of an hour you're set to go!

Joe
90 Syncro Westy Subaruized