Regardless of what style binding jig you end up using, if you plan on making one yourself, take your time. Binding is one of those tasks that will make or break the aesthetic of the finished instrument. The channels you get from your rig will only be as precise as the tool your using. A quick and dirty jig that's "close enough" will never give you precise channels- resulting in much more work on the tail end to get everything as close as you can.
The style of jig you originally posted (as opposed to the tower/cradle style jigs) is much more forgiving in working with imperfect side geometry. Yes, it will require flat sides- especially with the style guide shown in your post. But it will also follow any change in angle in your sides and still give you a true channel since it designed to cut parallel to your sides rather than perpendicular to the plates. In my (somewhat biased
) opinion, it's well worth learning to use.