How Shall I Suspend My Rearend?

The ladder bar option is appealing no doubt. But a good kit will run 400-700, maybe with shocks, now add all the labor to install and the price would go up a good deal. For 80% street I would say not worth it.
With alot of street use your going to likely, eventually, bend the locator bar, wear out springs and shocks faster and with the limited time you actually race it it will be hard, not impossible, to really get the rear optimally dialed in.
You can keep the SS springs, add ladders and floaters and not need coil overs but your going to wear out springs faster and add weight.

Just as an FYI. The springs are the best bet and cost effective as other have said too. Good luck