The Springfield adapter that's out of stock isn't really neccesary, it maybe makes that side of things slightly neater but you can just put the cable ferrule in the 'hook' on the arm.
With that caliper you need something to anchor the cable, something like a knarp.
Ideally on the front you'd use a caliper like an ad990 that has a cable anchor on one side of the arm.
The Springfield adapter that's out of stock isn't really neccesary, it maybe makes that side of things slightly neater but you can just put the cable ferrule in the 'hook' on the arm.
With that caliper you need something to anchor the cable, something like a knarp.
Ideally on the front you'd use a caliper like an ad990 that has a cable anchor on one side of the arm.