Tailslide:

Tower Hobbies sells the B&D trike retract set for $80. This includes the air tank, hoses, and valve.

They are 5/32" wire, putting 3/16" wire on the mains isn't hard, the nose is OK at 5/32". If you are good with your landings the 5/32" will be all right on the mains also.

If you need disconnects they are additional, and you'll have to buy an air pump.

Hope this helps.

Bill.