Tanks costs 20 QR per tank typically - try World Marine near the museum on the corniche, local dive clubs are around 14QR per tank. can't help you with the weights cost but they are quite cheap to buy, or if your desperate i can lend you some, i have a rather large collection of them since i am also a cold water UK diver...... where you need about 16 KG instead of 4 Kg......