FWIW, I went deep with Interactive Brokers for my last Fintech. It was the only place we could source real-time currency options data and we managed to reduce our total latency from market to database to about 10ms by using a NYC datacenter, which was enough for us. They had historic ticks too, but an inbuilt ratelimiter made it a multi-month project to pull serious volumes of data.
ib_insync was the python client library, and I OS'd the market gateway I built: https://github.com/dvasdekis/ib-gateway-docker-gcp