Get Yakama, Thule, or Malone .
The various interchanging parts they have for each sport change out in a matter of minutes.
Cradles, (saddles) are easier on the boats then J cradles.
If you are only paddling once a month, just get el-cheapo foam blocks
My preference is Yakama, and I have saddles, J cradles, bike carriers/ bike wheel carriers, gunnel brackets and ski holders. Makes carrying all the toys very easy.
Canoe/Kayak Storage Racks
Kayak Motor Kit