I've just ordered a genuine Volvo timing belt kit from Caffyns - cost me roughly £100
No need to buy aftermarket when OEM is that cheap. I'd imagine yours is the same kit, but you'd need to check to be sure. This kit does not include the water pump - that is an extra £80.
The only other brands I'd consider would be Gates or Continental.
BTW Aisin made the original water pump, so if you don't buy Volvo, I'd get an Aisin one
I'm sure another big name like Valeo, Febi Bilstein, or Continental would be fine, but the waterpump is an awkward bugger to change so I'd play it safe and fit OEM (which is why I've just bought a Volvo one lol)
If you're going to change the hydraulic tensioner, then the OEM brand was also Aisin. Volvo ones are £100, so I've bought an Aisin one for £60 from Autodoc (online but in Germany)
HTH