Box / Buxus - where to buy and/or nice alternatives?

[Latsia]

I need to get a decent batch of Box plants to cover the brickwork under our bay window. Does anyone know of an online vendor with competitive pricing for good quality (and decent sized) plants?

Are there any nice alternatives to Box hedging? It grows so slowly so I need to spend a bit more on slightly taller plants (about 80cm high) but it obv gets expensive.

Any suggestions gratefully received.