Have you looked on "pistonheads" in the classified section?
Altezzas are Toyotas so are reasonbly bulletproof, but like any car it depends on how well it has been maintained, they need to be regulary serviced so look for proof
Auto RS200 (tiptronic, mine) is a great all rounder if you do a lot of daily driving, but if modding is your game a manual has alot more options available...
A supercharged IS200 has similar performance and apparently cheaper insurance costs in the UK as the Altezza is an import it's in a higher bracket....
few nice supercharged IS200's for sale on this forum, might be worth a look?