No sorry I don't do custom installations.Well your system definitely has some extensive work for something that is not competition. I saw one of the cars at the BBQ actually remove their front windshield before playing music so it would shatter under the vibration and thought that was wild.
The stock system in the SRT is definitely lacking a little. It was horrible in the Limited X I had right before the SRT. In the SRT I can't get the audio settings to sound good either. It's nowhere near as bad as the Limited X but it still needs work. Songs either sound like they have way too much bass or not enough. The volume also seems like it should be much louder even though it's just a stock set up.
You don't install custom set ups for others?
The cheapest route is to get an LC2i line convertor for 100.00 and tap into the rear door speakers and use the rca outputs to run subs and tweeters.
The LC2i comes with a sub level control.
If you want better then get a PAC Harness which is 300.00.
If you don't have the capability of doing this then try a car stereo shop.
You can spend 500.00 for an LC2i setup or 3000.00 if you go with the PAC Harness.