Don't major the minor. I don't think dips would be a good main lift. They are a good tricep and chest exercise, but I would still have a main lift like bench press, floor press, overhead press or incline press. DB BP is also a very good exercise, and better for the shoulders for many.
Also I don't like the idea of going to failure every workout. The whole workout is almost build on triceps, it's hard enough as it is. the latter sounded better. Somewhere around 6 to 12 reps, for 2 to 5 sets would also be nice. Not much more than that. Then progress in weight.
Plus, I'm not sure you need four exercises that work the triceps, the last exercise might be quite useless.
Only reason I tossed in the last movement was because for the 10 weeks of the first routine, I didn't feel like it was doing anything triceps wise. Chest and shoulders felt like they got work, but triceps just don't feel like I do anything unless their is some sort of isolation.