Your best bet is to install the
Thule 422 Xsporter truck rack in your 1998 Dodge Ram 1500 truckbed. This is an all-purpose heavy duty truck rack system that is also ideal for transporting a canoe & kayaks. The 422 Xsporter also includes Xstops which are great for transporting a canoe, lumber and ladders etc. You can then connect two sets of
Thule 835XTR Hull-a-Port j-style kayak racks directly to the Thule 422 Xsporter load bars.
The best way to arrange everything is to place the canoe in the center of the load bars using the XStops, then you can mount a set of Thule 835XTR kayak carriers on each side of the canoe.