A turbo won't be easy to find. I don't think they were officialy imported to the UK, so if you do track one down, it's likely to be a left hooker. (Having said that, there was a RHD conversion on e-Bay recently.)
In standard trim, it pumps out about 165BHP, so it won't be as quick as your 3-litre, but it will have the balance of the TS. The Evoluzione was a special edition with much more grunt, but they're very rare (and expensive).