Hi - thought I'd add a word, here - we recently bought a new rad for our 91 Sportrak here in Ipswich, from a radiator specialist (rather than the local Daihatsu extortioners), cost us just over £100 new. The phone number is 01473 711131...the name of the company was Sheldrake & Wells (Radiators), and have an excellent reputation (may even be able to repair yours, as long as it isn't the plastic ends at fault).
www.sheldrakeandwells.co.uk