I would go with number 2. I have the first one (the charbroil with the offset fire box) and I am not particularly impressed with it. It does no hold temperature real well and its a pain in ht ebu to get the temp to where you want it. Add the lack of a water pan (helps cook faster and keep the meat more moist) and it is not the best option out there.
I like the second one becuase of the size; the water pan and the fact that its gas will make it easier to control the temperature and it will take less time to get it going. Now all of you charcoal fans a going to jump on the flavor aspect; but you are looking for smoke flavour; not charcoal flavor.
As for a rub; try this
8 tablespoons light brown sugar, tightly packed
3 tablespoons kosher salt
1 tablespoon chili powder
1/2 teaspoon ground black pepper
1/2 teaspoon cayenne pepper
1/2 teaspoon freshly ground cumin
1/2 teaspoon garlic powder
1/2 teaspoon rubbed thyme
1/2 teaspoon onion powder
You've already received some good advice. I use a ceramic cooker which is by no means inexpensive. I want to get an offset some day when I hit the lottery so I can get a Trager Pellet Smoker But, whatever you get will just scratch your itch...
When I do ribs, I usually do a 3:1:1 or 3:1.5:1. Meaning three hours unwrapped, 1-1.5 hours wrapped in foil and then 30 minutes to 1 hour unwrapped to firm them back up a bit and give them a glaze. Only mop them during the last phase but you can put a little apple juice or something similar in the foil with them.
Ribs are done by feel and not temperature so it takes practice.
I also prefer spareribs as they are meatier. Google "St. Louis Spareribs" and you should find some tutorials on how to trim them for best results.