I agree with richoso1 and the others, get the Gold. (NOT the Silver like BBQ Bubba has :) )
All kidding aside, I prefer the Gold to the Silver. I have heard arguments on both sides, but the benefits I see to the Gold is:
The Ash Catcher. The Silver does not hoave this, but proponents of the Silver will say that the ash catcher will interfere with airflow. After 3 years of nearly daily use, from everything from high temp grilling to long offset smokes at 240*, my personal belief is that that argument is not true.
Second Ash Can pro: I got 2 dogs. They see anything fall onto the patio, coming from an area that smells awesome, and they might bite it. Don't need to put the pets through that. as the small coals pass through the charcoal grate, the ones that fall out are safely in the pan.
Third Ash Can pro, is one that doesnt apply to me. I cook on a concrete patio. But if I cooked on a deck, the opposite of the dog eating a coal is burning the house down if the coal lands on the deck.
The only other attribute to the Gold is the hinged cooking grate is standard. I use this with each and every cook, as I leave one hinge over the coals always open. I can low cook at 240*, lift the lid 1", expose the coal side, drop in a little chunk of hickory, and reclose the lid with about a 5* temp drop, recover in about 30 seconds.
I have perfected ribs and pork loins using this offset method.
Two more Weber add ons I use:
Weber rib racks. I use two of these, end to end, so the ends of the slabs stay straight and don't "flop over" the end. I also bend the end tynes in toward the center, to allow the curvature of
the kettle to properly miss hitting the racks.
Cast Iron smoker box: Don't use this that much, but when using lump, I can set this on top and drop chips and pellets into it for smoke
Good luck!