Shop for the trailer you want. If it fits within real and common sense weight capacity for your truck, great. If not, buy the truck that it takes to make it right. That's it. You will not be happy if you buy a smaller trailer or cut out that bedroom slide to save hitch weight or go with a travel trailer if you want a 5'er and then it's all going to be frustrating. Just get the right trailer and THEN decide on the truck. Nothing says you have to even take the trailer home. Pick the trailer, heck even buy it, then take it to the scales and weigh your truck and the trailer. If you are not 100% sure, go buy a truck that makes you 100% sure. Even if that means limping home and then not moving the trailer again until you can get the truck done. Seriously, don't feel pressured, if the money is an issue then shop within your limits and that might mean some used gear instead of all new trailer and new truck!