I have a 22" with lid and a aftermarket non blackstone stand.
The blackstone stand is OK if you can get a folding model vs. a fixed stand that does not collapse for transport.
I prefer the 22 vs. the 17 because it has 2 burners and can generate more heat.
The 17 can struggle to get hot on cool windy mornings.
On a nice 70º day both 17 & 22 work well. However on colder mornings the 22 shines and generates plenty of heat vs. a 17.
Get a lid it makes a difference and is sometimes invaluable.
Wind screens are also good to have.
You don't need them often, but when you do they are nice to have.
Also get the proper hoses and connections, I can use LP from the RV or I can connect to a standard 20# portable lp tank.