Jeff at Gtech (01858 535411) has a fresh built, blueprinted superstock motor for sale. No throttles with it and it's not as cheap as a stock motor but depends what you want from it. Stock motors are still pretty rare and fetch good money. "Race" motors are even rarer.
Kaemna Ducati in Germany have one. It's not cheap (in fact it's eye-wateringly expensive at nearly 6K Euros) but all their engines are fully refurbished, serviced and very clean. Takes the guesswork out of buying a 'new' motor rather than one off eBay or from a scrapper where you have no idea of what its history is.