We have a coleman portable grill, the one with the table. All fits into a bag for transport. I have a tap that goes to the propane tanks on the front of the TM, and allows extension hoses to hook up to the grill (with the proper adapter, naturally). Works great. The grill would be large enough for a family of 4, and it has interchangeable grates for multiple purposes, including using it as burners for pots if you wanted to cook outside. Plenty of BTU, starter button, etc.
Let me pull some links:
Roadtrip LX:
http://www.coleman.com/coleman/colem...d=27110&brand=
Currently on sale at Campingworld:
http://www.campingworld.com/shopping...ill-blue/35188
Tank tap:
http://www.rvupgradestore.com/Marsha...-p/66-8822.htm
This allows for any 12' M/F extension hose to be attached:
http://www.rvupgradestore.com/Marsha.../marsh-efa.htm
The other end just screws into the back of the grill. The connector is the same as on the toss-away propane bottles, and the pressure is high-pressure (because you're tapping into the line before the regulator off the propane tank) so the grill thinks you've got a bottle attached.
This set-up allows us to use the 20# tanks we already have on the TM, and the tanks are still both connected to the TM, so we're only using propane out of one tank for either indoor or outdoor use. This allows us to use up one tank at a time, and then just refill that tank when it's empty. I keep the tee and the hose in the compartment on the front of my slide-out, and just quickly attach them to the tank in use just prior to sliding the LR open (it's difficult to get to the tanks once the LR is slid out on the SL models). Aith the ACME nuts, there are no tools involved, so it only takes a few extra seconds to attach during set up.
We set up the grill near the tanks/tongue on the door side of the TM, usually just outside the awning. DW likes to cook there, as it's convenient to get inside for food, etc.