I'm thinking about a Saito 1.25 too and have already checked into availability. They're expected in the US in December, but Paul at Just Engines says that the UK is usually about 4-6 months behind (!)

The price in $ is about the same in the US as the UK price is likely to be in £. But by the time you've paid for delivery, VAT, import duty etc it works out about the same by my reckoning. And you won't get any after-sales service on a direct import if you have a problem with it. Then again, you'd probably be unlucky to need a repair under guarantee from what I've heard about Saitos.

So, I guess it depends how bad you want one whether you're prepared to wait.

Hope that helps,
Phil