For evolution stones, you will need to post in the Pokemon Evolution Request thread, and send trade to Pandashroom Pogeys ONLY when quoted. RP is not required if all you need is an item to evolve.
Everstone: Equip this on your Pokemon to stop it from evolving.
Item can be purchased at any time. Send trade and let Qixel know.
Price: 200g
Fire Stone: It's radiation evolves Vulpix, Growlithe, Magmar and Eevee.
Price: 3000g
Water Stone: It's radiation evolves Eevee, Poliwhirl, Seadra, Lombre, Staryu, Slowpoke, Clamperl (Into Huntail or Gorebyss), and Shellder.
Price: 3000g
Thunder Stone: It's radiation evolves Pikachu, Electabuzz and Eevee.
Price: 3000
Leaf Stone: It's radiation evolves Eevee, Exeggcute, Gloom and Nuzleaf.
Price: 3000g
Ice Stone: It's radiation evolves Eevee, Porygon, and Porygon2
Price: 3000g
Moon Stone: It's radiation evolves Skitty, Sneasel, Nidorina, Nidorino, Happiny, Jigglypuff and Clefairy.
Price: 3000g
Sun Stone: It's radiation evolves Gloom, Onix, Rhydon, Scyther, and Sunkern.
Price: 3000g
Dusk Stone: It's radiation evolves Murkrow, Misdreavus, Dusclops, Gligar and Houndoom.
Price: 3000g
Dawn Stone: It's radiation evolves male Kirlia, female Snowrunt, Togetic, Minccino, and Roselia.
Price: 3000g