40 gal dirt tank

hi all just starting a thread about my dirt tank im in the process of starting i have used john innes seed sowing mix which was soaked and skimmed to remove the floaters and then baked in the oven i have laid this around an inch deep on the base of the aquarium i then topped this with around half inch of silver sand and then capped this with around 2 inch of black 2mm gravel

does this sound ok to everyone any criticisms are welcome as its my first dirt tank the plants are due on tuesday i have 200 individual plants in total including

5 x Elodea Densa
1 x Aponogeton Crispus
5 Eleocharis Parvulus (dwarf hairgrass)
10 x mini Amazon Sword
5 x Bacopa Monnerii
5 x Twisted Vallisneria
10 x Sagittaria Natans
5 x Rotalla Indica

5 x Cabomba Caroliniana
5 x Cryptocoryne Wendtii
5 x Hygrophilia Polysperma
5 x Ludwigia Mullertii

5 x Vallisneria Spiralis
5 x Ludwigia Natans
10 x Mayaca Fluviatilas

5 x Rotala Macranda
5 x Hydrilla Verticillata
5 x Echinodorus Latifolius

5 x Echinodorus Paniculatus
5 x Eleocharis Vivipara
5 x Salvinia Auriculata
5 x Cryptocoryne Ciliata
1 x Nymphea Stellata

any input appreciated there are around another 80 more mixed stems aswell that depend on the stock that they have i gt them all for £30 pounds is this a good price ??

also any fish suggestions for the stockiing im going to get some malaysian trumpet snails as i have hadf them when this tank was set up before and i was thinking mayvbe tiger barbs but any other thoughts????

thanks