The first requisite for a July 4 barbecue is a grill-friendly terrace or park. The next, a terrace- or park-friendly grill. Coleman’s RoadTrip NXT 200 barbecue ($200 at Sports Authority, 51–30 Northern Blvd., Woodside; 718-205-4075) has 20,000-btu propane heating (tank sold separately), dual adjustable burners, and space to flip eighteen burgers — all in a sleek, mobile package. Simply collapse the wheeled legs and roll the 33-inch-long unit like a suitcase to your next backyard cookout, block party, or riverfront destination. In seconds, it clicks back into cooking position, with tool holders and side trays to boot.