Web App's Use .local URL

Hi,

We currently have a number of Web App's that use the URL example.company.local.

These Web App's include team sites and SkyDrive (My Sites)

Sooner or later staff will need to connect to team sites, Skydrive, share documents etc over the internet without a VPN connection.

What's the best way to change the URL within SharePoint for current Web App's so team sites and SkyDrive is accessed via exmample.company.com insteda of .local?

Also, what's best practice for authentication?  Should it be safe enough to use https:// and for the users to be prompted for their domain name and password hwne connecting to https://example.company.com? 

Thanks