Hi zzz,
Office 365 E1 subscription is using the Lync server 2010 at this point, and will be upgraded to Lync Server 2013 in the feature. For more information about the service upgrade, you can read the article below:
Office 365 Service Upgrade Center for Enterprise
http://community.office365.com/en-us/wikis/office_365_service_updates/office-365-service-upgrade-center-for-enterprise.aspx
Regarding the Lync voice feature, you can deploy Lync to phone for your company. The Lync to phone feature is included in Lync Online Plan 3. You can purchase Lync Online Plan 3 licenses in the Office 365 portal, go to Admin > Subscriptions: Purchase. You also need to contact a Lync-to-phone provider to get the phone numbers. For detailed information about Lync to phone, you can refer to the following articles:
Microsoft Lync Online for Enterprises Service Description
http://www.microsoft.com/en-us/download/details.aspx?id=13602
Connect Lync Online to the telephone network with Lync-to-phone
http://onlinehelp.microsoft.com/en-us/office365-enterprises/hh781536.aspx
Video: Configuring Lync-to-phone for Office 365
http://community.office365.com/en-us/blogs/office_365_technical_blog/archive/2012/08/14/video-configuring-lync-to-phone-for-office-365.aspx
Thanks,
Mindy Pan