Hi Richard,
I'd second Hetzner. They are in Europe so latency should be pretty good from England. I don't build GHC regularly but I have just purchased a machine similar to
this one from Hetnzer (with only a single 500GB Samsung 500GB 970 EVO Plus) and it makes a meal of my client's application with many dependencies. We use a Hetzner machine at work as a CI server and it hasn't let us down yet.
Note that I used to use GCP because my MacBook Air wasn't really up to the task. I'd use tmux and emacs so things were pretty good (on a free trial with preemptible — shut down your machine when you're not using it and it can be pretty cheap). However, SSD speeds are not like those you get with a dedicated server. IIRC 300Gbps vs 1000Gbps.
Cheers,
Steve.