Small tropical fish tank for fighting fish

I am looking for a fish tank suitable to house a siamese fighting fish min size 5 litre but must be for tropicla ie include heater, filter, light. Nothing large but small maybe to keep a few other quite fish with the fighter. Biorb type be fantastic however VERY limited on funds so no more than £40 iclusive of P&P or in the Orpington, Kent area for collection, must be in full working order. Lower the price the better and must accept cheques or cash on collection if local enough as cannot use pp