first, who doesnt love puffers, there awesome!
what would be the size tank for the figure eights? if its a 55 gallon i would put in about 6 of them. also, i would start with low salinity brackish (1.003) and work up to about 1.014 for figure eights
i would put 2, maybe 3 GSP's in the 55 gal and go from 1.007 to 1.020.
i got my instant ocean hydrometer for 13 bucks and salt to make 10 gallons of saltwater for 8 bucks.
i used white sand for a substrate
i dont know about tank prices though (sry

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