The linkage kits are expensive because they are usually designed to be used with a bell crank system and sideways oriented dual feeds. In this situation, a ton of inflexible linkage is needed, and the kits are spendy. If you are able to orient them front/back you will capitalize on two things, first, the carbs work better upon acceleration, and second that the linkage is basic, just run a pair of heim joints on a rod between the carbs and make sure you take out all of the slack. E-mail me if you have any questions.
P.S. They warm up just fine at the river!