Paid Market Testing

I am planning at a new startup and would like to a-b-test several elements (such as the brand name / logo / sales pitch) before the actual product launch.

Ideally, I would love to pay a service money to show two versions to a lot of users and have them pick their favorite. Of course, once the service launches there will be a-b-testing with the real-world users as well - this is only for the pre-launch phase.

The only general service that to my knowledge is currently suited to do this is Amazon's Mechanical Turk which is unfortunately unavailable for Non-Americans.

A Google search for paid questionnaires turned up a lot of services that allowed users to take the questionnaires but none that allowed me to post one for pay.

The key is that the people taking the questionnaire have to be provided and either micro-paid by us or paid by the service-provider with us paying for the service. (As opposed to a classic questionnaire where we provide our own users.)

Are there any (trustworthy) services for this purpose? A breakdown of gender, age and location groups for the answering people as well as the ability to leave detailed feedback would be perfect but ultimately a simple percentage voting will do as well. Also, pointers on other ways to reach the same results are also greatly appreciated.

How about this list - "Quora - What are some crowdsourcing services similar to Amazon Mechanical Turk?" Some are alternatives, some are meta-platforms built on top of mtuk and may not have the same US-only restriction.

If appropriate to your market audience, you could try testing a variety of Facebook ads and work out which is working the best by the click through rates you get.