1. I am a senior bowler
2. I am rev dominant
3. My speed fluctuates between 13-14/mph
4. I am changing my bowling line from inside to outside, just to increase my options
Sounds like your lanes are extremely spotty, and inconsistent. In that case, I believe you are on the right track using a brace that gives you an "up the back " release. This tends to simplify your game and take a lot of variables out of it when you do have to adjust to the lanes because of their spottiness. However, I would tend to go with a medium to strong piece, rather than a weak one. If you are using a brace because of a past injury, then you are limiting the amount of revs you can impart on the ball, to begin with, so no need to compound that by using a weak piece too.
I really believe using a medium-strong piece would force you to learn when and where to move your feet when the lanes begin to break down. Also it would afford you the chances of learning how to use the dry areas to increase your carry. Please keep in mind, this will also force you back inside rather than limiting you to the down and in area.
If you are truly intent on staying in the gutter to ten area, than a shiny piece is the way to go. Just my two cents.