The kits from NB and my LHBS have all the ingredients/qty's listed. I would not by a kit if it wasn't. That is how I learned. I would find a style I like. Then check different recipes for common ingredients. I found most PA's were 2 row based and wheats were 60/40 wheat/2row. You can change the 2 row to marris otter, munich or vienna. You can change the wheat to US,Ger etc. The specialty malts/hops varied quite a bit but the base stayed at 85-90%. I think my store relies on 2 row to keep the price down. This made me think it can't be that complicated. You can match the origin....like German grains/hops yeast but it just means you need a bigger supply of various grains on hand if you want to experiment.
The crystal 20L,40L,60L are just browned for various times to get darker. You can brown 2row in the oven and get similar results. You can substitute 1/3 60L and get pretty close to 20L. I'm no expert and might be wrong on some of this but it helped me understand how it all comes together. Otherwise it overwhelms you with all the various ingredients.