If you have rub marks for the snubber, you probably are bottoming out. Yes, the parts counter shocks are probably junk and you need something better. How much better depends. Stock leafs are supposed to appear nearly flat when installed. If you pull a string on them, I bet they have 1.5-2" arch in them. This is normal and preferred. Composite springs are a bit pricey and may not solve your problemsif there are other issues going on.
Depending on the snubber, you may be able to just cut it down and gain clearance. The typical MP unit with the multi-hole snubber mount is too tall for most stock spring applications as it was designed for SS equiped cars with lots of arch. Trimming these down usually gain the room you need. I've had to do this on every street car I've used them on with stock style leafs. My drag cars I did not. If your stock style snubber is hitting, then ditch it altogether. Unless you're doing drag launches, you probably don't need it.
Shocks - if you are a handling newby, I wouldn't necessarily recommend dbl adjustables unless you are meticulous about keeping records of settings. Most dbl adjustables have combined setting that amount to around 200 possible combinations. That is a lot of ways to go wrong if you are new to spring frequencies and shock reactions. Not only that, they are expensive. If you are a more set it and forget it driver, I'd go with fixed valving such is Firm Feel Bilsteins. If you do like to tinker, start with a single adjustable.
