Ouch with regards to the pricingDef Tech has a wide range of ceiling speakers that would work, though almost any of them would be in a higher quality bracket than the Procinema speakers. Look at their DI and DT series products and decide a budget.
In-Wall/In-Ceiling Speakers | Definitive Technology®
You have quite a good receiver there, far more capable the 5.1 set you have (for now) can deliver.
Outwith my budget I'm afraid, looks like the S/H route is way to go on thisI like my KEF speakers and they offer a LOT of choices with in-ceiling speakers. All of them handle the power your receiver could put out. I just don't know what you would have to pay because I'm in the US and assume you're in the UK.