Cucumber driver recommendations?

I am on a project which has been writing acceptance tests in Cucumber
which
drives the application via capybara and celerity. The tests have been
getting more and more flaky over time as celerity frequently looses it
connection to HTML Unit. I am looking for suggestions on more stable
web
drivers. We have used Selenium in the past and it also tended to be
flaky.
My project is using jQuery so a simple HTTP library is won’t work.

I think the more long term solution is to have less full stack UI
testing
and more Cucumber tests which hit the core business logic in the models.
However, I have a set of existing Cucumber tests could be more stable.