I have the 17" for trailer and the 22" at home. Both have the metal covers.
To fit a metal cover to the Walmart 17" rear grease trap model, simply add 1" spacers and longer bolts to move the cover rearward. I found the best price for a 17" cover to be directly from Blackstone. The Royal Gourmet 21" gas grill
bag works perfectly for this setup and holds 2 bottles. If you flip the top and haul the griddle that way, the aluminum pop rivets wear on the cooking surface making an unhealthy mess, I replaced them with 5/32" stainless steel rivets.
A
conversion kit is available to easily connect to an RV. Do some searching for better prices and more options.