Tornado Drop tanks here:

http://www.ebay.co.uk/itm/EXTERNAL-FUEL-TANKS-TORNADO-/290679241180?pt=UK_CPV_Aviation_SM&hash=item43add539dc#ht_2041wt_754

Though these are the 1500 ltr versions which are made from Phenolic Asbestos which would be a ****** to cut and may cause some consternation in the H&S world.

Better the 2250 ltr ‘Big Jugs’ but they are like rocking horse manure. Stainless Steel and a far bit of room in them for a monster engine.