301 redirect vs parking

I have several domain names registered, each a slight variant of each other.

E.g,

fastcar.com fast-car.com fastcar.co.uk fast-car.co.uk

etc..

I don't wish to be penalized for duplicate content or spammy links by any of the major search engines.

Should I park them all directly on the main domain I wish to promote, 301 redirect them to the main domain or not use them at all?

If 301 redirects are the best option, would having two web hosting accounts be better than one?

Example:

Hosting account 1 has fastcar.com linked through the dns.

Hosting account 2 has fast-car.com, fastcar.co.uk, fast-car.co.uk linked through dns, and 301 redirects pointing to fastcar.com

Thanks

I'd 301 redirect and then specify your preferred URL:

http://googlewebmastercentral.blogspot.com/2009/02/specify-your-canonical.html