This is what I'm using right now. It actually was built by my brother and belongs to him. It is what we call a "down draft" design. On the smoker this size, we put the firebox in the middle to keep temps as even as possible.
The fire box is inline to transfer as much heat as possible to the cooking chamber. The walls to the firebox extend nearly to the top of the smoker, causing the smoke to enter at the top. (The rack is where we put foil pans of water when cooking ribs.)
The exhaust exits the cooking chamber below the cooking grates. This allows temps to stay even and ensure the smoke travels over what you are cooking.
This frame holds a food prep table. This year, my brother hopes to replace it with a small propane grill (6' x 24" or 30" tank).
Here is a small unit my brother built for his patio. You can see the exhaust stack extending below the cooking surface.
This did not have an inline firebox. The bottom RH corner of the pic shows the exhaust entering the top of the smoker. The firebox doubles as a charcoal grill when he is not smoking. (Sorry, I've lost the pictures of that end of the smoker.)
Stonebriar had Horizon build a custom rig for him with a vertical chamber that allows for smoking cheese, finishing ribs after they're foiled, or keeping foods warm. Here is the link to his thread:
http://www.smokingmeatforums.com/t/129632/new-build
I posted all this to say that in one sense, you get what you pay for. In another sense, how "good" do you need? I've seen guys spend the price of a new rifle just to make the rifle they had shoot a group a tenth of an inch tighter than it did currently. I can't justify that whether we're talking guns or smokers.
In Stonebriar's case, he started with a Bandera. He put out good product, but had to babysit the smoker the whole time. It was VERY difficult to do his cheese. The Horizon got him away from that and gave him more cooking space. He also had to save his pennies for literal years before he could afford the new smoker.
**Addendum: I thought you might be interested to know we generally smoke a large quantity of meats when we fire the smoker up. I then freeze the meat and pull it out for a meal when we're stuck on something different to eat. When there is nothing in the freezer and the folks want a pork-u-pine or one of my other dishes, I will use my charcoal grill as a smoker. I'll build a fire on one end and place the product at the other. I will use the smoke stack on the meat end and close the other off. I will use charcoal with mesquite or hickory wood mixed in and then add some other chips on the cooking grate to smolder (minion method, I guess). It is similar to a UDS and puts out adequate meat. If you notice, it does have a pretty good gap at the bottom.
Sorry for the long post. I hope it gives you a different perspective. Hope you have a great New Year.