I've not used their Slick and Suds, but have used Slick and Foam, which Poorboys advertises as more of a pre-wash. Other soaps I've tried that I thought foamed well and had good lubricity....McKees Extreme Foam, Chemical Guys Honeydew and Meguiars Gold Class.
Here are some good one's to consider. These all have a good amount of suds and lubricity.
Meguiar's Hyperwash
Jay Leno Vehicle Wash - This one surprised me. Was told it was sun safe by the Leno's Garage folks.
McKee's Xtreme Foam
Optimum Car Wash
CarPro Reset - Good but it is a bit on the strong side and will degrade a wax or sealant faster. Great for a coated vehicle.
McKee's SiO2 Wash - It is good but on the expensive side. Sun safe as well. It definitely leaves something behind as I noticed some change in hydrophobic properties.
Ok shampoos for me
Gyeon Bathe - too expensive for the amount and dilution ratio.
Gyeon Bathe Essence - Seems a bit weak and doesn't have that high suds like regular bathe. I tend to use more than the recommended ratio to get it to perform better. Thus not making it cost effective.
CarPro Reset is great. McKee's Xtreme Foam, Power Wash and Sio2 Auto Wash are great too. I oftentimes use CarPro Reset on the body and Optimum Car Wash on wheelwork. I keep forgetting to buy Meguiar's Hyper Wash.