Yeah that looks good. I would still test a little bit in a bucket or cup for a couple of days to check how it affects the water. Basically you want whichever soil you can find that has the least amount of limestone, nitrate and phosphate and preferably without many bark chips and other large organic particles. Pond soils tend to be a good bet too.
I forgot to mention that I also mixed my compost about 50/50 with sand to keep the system quite lean, then capped with pure sand.