Lowes has a 10 pack of Weber pans 2" high . I think they are $9.99. If you are using the entire grill surface you may need 2 or 3 depending on EX4 or 6. I know Amazon has cheaper ones but these work and readily available.
I put a regular half size tray along the very bottom underneath the flavorizer bars... the idea was compliments of one of Harry Soo’s videos. Seems to work well and there is no impedance Of smoke
I got these $18 for 30. They are 13" x 9" x 2" so takes multiple if need to cover whole grill. I only use them with fattier meats to make cleanup easier.
Amazon.com : Stock Your Home Disposable Aluminum Foil Broiler Pans (10 Pack) - Broiler Drip Pans for Oven - Durable Broiling Pans with Ribbed Bottom Surface for BBQ Grill Like Texture - 13x9 Inch Broiler Pan : Garden & Outdoor