Kevin,
The dealership is robbing you bind. I bought my SC for $4400 and my dealership installed it for $600. I believe you would be much happier with the $5K spent on a SC instead of the bolt-ons.
I've been involved with muscle cars on and off for 25 years. Bolt-ons can only do so much.
BTW - I'm looking for a 1971 Plymouth GTX/Roadrunner with a 440, A/C, PS, PB, and AT. There's one on ebay, but the guy is asking too much for it. If anyone knows of one for sale, let me know!
eBay GTX