I picked up a Holiday chest freezer from Lowe's, the 5 cubic feet model. This will be big enough to hold 3 cornie kegs and the CO2 tank, or possibly 4 cornies if you mount the CO2 outside. Here it is brand new.
First, I took the lid off.
For the inner collar, I measured the freezer and cut 2x6 pine and secured it together using angle brackets and wood screws.
Here is the inner collar on the freezer.
For the outer collar, I got some 1x8 red oak. This stuff is expensive ($25 for 6 feet of 1x8) but it is beautiful. I only put the oak on the front and the sides, no need for it on the back. I used my father-in-laws miter saw to cut the ends at a 45 degree angle.
I clamped the oak to the pine inner collar where I wanted it and drilled for 1/4" holes on each side for the bolts. I used 1/4-20x3" brass bolts with nuts and washers to secure the oak to the pine inner collar.
Here is the freezer now with the collar on. I still need to drill the holes in the front for the faucets, stain the collar and caulk the gaps with silicone. All of the hard work is done though!
I also am thinking about possibly painting the freezer itself black. I think it would look a hell of a lot nicer than white. Someone on here posted a thread of their same freezer that they painted red, so it's do-able. I haven't decided for sure yet. The stain I am using is a red mahogany, so I think black would look really nice with it.
I will post more pics when it is done! Sorry if these pics aren't that great. I took them with my phone in my dark basement so they aren't the best.