NO PROBLEM!
I use a set up just like you describe to run the gas grill and LP converted Yamaha gen-set from my 2-30lb. LP tanks.
The adapter that you need is made by Camco and allows you to cnnect an externalLP appliance to your existing tanks. It threads right onto the tank, you attach the hose that leads to the trailer, and you have a second port for your accessory. Stock # is 59133 for the 'T' only, or 59143 for the 'T' and a 12' hose.