There's two possibilities here - that HPI will supply the full range of HW speedos or that they will supply only HPI-badged speedos made by HW. My money is on the latter. If that's the case it will be the current one plus the new v3, both with HPI badges. If we want something else, I am afraid the internet beckons unless someone allows Gaintcod to actually get some stock of the car speedos that are on their website.
more information on the speedo.
I think Kyosho.de sells the Hobbywing in Germany also so might be that HPI brings both to UK.