Exchange 2013 - Sophos Products

Hi,

I've been asked to design and deploy an Exchange solution for a small client who now has 200 users and they might grow later. I'm new to the Sophos world so my questions might sound dumb but need urgent help because based on the correct information we might buy this product soon.

I learnt about Sophos from this website. http://www.alexheer.co.uk/it-blog/replacing-microsoft-tmg-2010 

Since Microsoft is not releasing any version of TMG and configuring TMG 2010 with Exchange 2013 is not directly Out of box but needs manual configuration. Also, I need hardware device which acts as an email gateway to send/receive email. At this I thought what solution or device does Sophos has to provide these funcationalities:

1. Send Email from Internal to External World
2. Receive Email from External World to Internal Users

3. Reverse Proxy (Provide similar functionality like that of TMG to publish CAS Servers securely behind firewall).

Now my question is:

A) Are all these three functionalities supported in Sophos products?

B) If yes, is it in one device or multiple devices/subscriptions etc? I'm not sure if we can configure/point multiple public IP's on devices - 1 for Reverse Proxy & 1 for MX record using NAT on external Interface.

C) Even if it is separate products/subscriptions does it support all that needs for secure email?

Thanks in advance.