I use Yakima rack solutions to my carrying problems. The racks and accessories are modular and the parts fit interchangeably. I have reconfigured the system many times to go from car, to camper, and back to truck.    

   A lot will depend upon how you want to mount the rack or use a tariler.

There are 2 major rack companies that have componet rack systems and hauling systems but the parts between the 2 companies are not interchangable. So you might want to consider which barnd you want to go with.

Yakima fit my car

Thule Buyers Guide

Because you have a pickup type vehicle there is no roof rack but Yamima makes a bed rack and a trailer.

Thule does not appear to have a mounting system for the 2011 Ford Ranger in any model.

   Pick up trucks with caps cannot always use the fit charts but have to be inventive with the components. For example, there is no fit chart for a Northstar pop up truck camper but you can find the mounts that screw through the roof that take the standard posts that support the bar and cradles. . 

 Also a cab mounted rack might not be listed but you can mix and match a typical rack mount with the door configuration and have one rack on the cab and a different style on the shell.

I have known some builders that just screwed or strapped wood cradles to the roof of the cap making a boat carrier. After all we are building "light" craft.

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If you can build  boat figuring out the rack should be as easy.

Note that if your top needs added support for a 92# boat on top it would be unusual. But you could add additional framing doublers inside. My truck uses the Yakima bed rack system. It is a full size pickup with slightly oversize tires. I need a step stool to get into the bed. (senior citizen)  Either way it is my observation that after say a 25 mile paddle a 92 # boat seems like a 192# boat when you have to lift it up a great distance.

   I am a fan of Malone products: http://www.maloneautoracks.com/

especially their "Sea Wings"...for these you could literally bolt a rear set thru the top of your camper top,  or to any shape cross rail, and a front set above your cab and load them from behind your truck, lift up, and slide forward.   You can still fit 2 kayaks easily side by side flat because the sea wings can be mounted to overhang the side of your car a little if you want.  The kayaks also take up less vertical height than "J" racks.  They also are a little "springy" so that strap pressure holds your kayak in place real nice without having to put a lot of stress on your kayak.

http://www.maloneautoracks.com/seawing.php

All Malone products are very high quality and they stand behind their products for life.

Curt

   thanks guys. Looks like there are several options to explore. I've already got too many trailers around, so I think I'll go a different route there.

One thing we didn't mention was a hitch extender. My friend with the Ford Ranger, affectionately known as "Whitey" uses a hitch extender for her Ocean Kayak 14ft SOT.  Technically I think she should have lights on it but in daylight a flag works.  Basically the boat sits one end in the bed and one end on the extender. 

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A lift to the tail gate height is easier than a lift to the top of the cap.    

   I bought a removable ladder rack for my pickup at Harbor Freight 99$.

It works great to carry a single kayak, and when I don't want it on the truck just slides out of the mounts.

Also it carries the kayak high enough that I have no concerns about other vehicles.

http://www.harborfreight.com/250-lb-truck-ladder-rack-66187-1789.html