You need to step away from Google and cool 'new technology', considering if you go look at Googles long list of products they've delivered, then redacted a year or more later, it gets very messy for business use. There is a reason why businesses won't budge from MS Office, and that's because Microsoft have continuously updated their software, albeit many issues along the way, it is still in the marketplace and very backwards compatible in opening older document types. Office is
THE industry recognised business software.
The simple fact you're looking at cool things versus stability is screaming that you need to seriously get some external local help to assist you with this. The fact that you're going to create them a business website using forum software also screams you aren't a web designer and shouldn't be touching that aspect of their business for them. You don't build a company website using forum software, you use a CMS... and the reason for that is because a business needs to deliver specific information about themselves as their priority. Xenforo's responsive design is laughable compared to existing responsive implementation easily available for Joomla or WP. Move some of these around in your browser and tell me if XF style comes close:
http://demo.rockettheme.com &
http://demo.gavick.com
You made a decision about their company website based on your limited knowledge in styling a forum software that suits you, NOT THEM.
Things you're saying screams that your ability to perform this job to an adequate standard for what the business needs is well below a basic benchmark knowledge. @
Tracy Perry has stated you can get experience, which is true, however; he also stated he was programming things way before and had quite a foundational knowledge. You do not display that foundational knowledge IMHO Dre, and you really need to consult a local IT guy to help you with this, and not ask questions on a forum when you have no actual understanding or direction for the task at hand, or its obvious requirements.
Gmail is about the only product you should consider,
IF, the clients needs require anywhere mail access and
THEY want all their sent mail to remain in a single location. That is the problem with normal email delivered across devices, sent mail suddenly becomes lost and that can be disaster for any business. Gmail can be upgraded to a pro account per email address, per annum, and the mx routed to gmails server, so that you use your own email address from your domain at all times which is a requirement for business professionalism, yet all in and out mail is routed and stored via your gmail account.
Here is some advice which I feel you have skipped completely over... where is your list of questions that you put to the business owner on what they need?
Whilst there are statements above about the customer not always knowing what they need, that doesn't mean you do stupid crap like use a forum software for a business website. That type of statement is often more equipment reflective to cater expansion of their business.