Electric exhaust cut outs

Hey guys, I have a 68 Cuda,340s. I am in the process of updating my car after 21 years and putting in another motor and will be installing my TTI headers. I am interested in putting in electric exhaust cut outs. For those of you using them, what would you recommend I should look at. Are they worth it and do they work good? Power gain? This is a street car but I would love to flip a switch to get that sound and power they provide. Any suggestions or thoughts on the positive side would be appreciated.
Thanks
Sparky
Think I will throw my money at something else for the car instead buying head aches. Still have time to decide. Waiting for a hoist I ordered, need it now.