If it wuz me, and of course it ain't, I would buy a Dragoon instead of a Walker. Colt only made, what, about 1100 Walkers? The very next year, he recognized the things that needed correcting in the Walker, ie: a latch under the muzzle to secure the loading lever, and the thing was just much bigger than it really needed to be. He cut the barrel down, reduced the chamber capacity, and came up with the First Model Dragoon. He didn't even try to fix the problems with the Walker, just moved right on to the next design. It's nice to think of the Walker as the most powerful revolver of its day, but don't forget they used to blow up quite regularly. The powder capacity was just too much for the iron used in the cylinders.
Like I say, it ain't me, but if I was looking for a big bad looking C&B Colt, and didn't want the usual 1851 Navy or 1860 Army, I'd get a Dragoon. Just This Cowboy's Humble Opinion.