Fast and reliable host for database + AJAX intensive Rails a

Hi

I’m trying to convice a client to use Rails for a new commercial web
application. At the demo/preliminary stages, our monthly hosting
budget is 20$-40$ (naturally it would increase with consumer demands).

We need a fast, reliable host at that cost range. The application has
to be fast, especially the AJAX parts. Also there’s a lot of
database-querying involved, so the database has to be fast and
responsive. I cannot overstress this: if the request/response delay is
too long, I won’t be able to do the project in Rails. And if I go with
an unreliable host, the whole project might be marked up as a failure
and go down the drain.

Could you suggest a suitable hosting solution?

Regards,
Alder G.