Help setting up VPN on 2 Sides

Hi there,

now i´m on business with Mikrotik, as for me it is the best routing devices on the Market.

So, I am new to this subject and want to set up my 3 devices.

The situation is:

Site 1:
VDSL 50/10 Mbit
MikroTik RB2011UAS-RM 19" Rackmount

Site 2:

Cable 50/2,5 Mbit
MikroTik RB751G-2HnD

Sub Site 2:

MikroTik RB2011UAS-IN

So, now there is, what I want to realize:

The Site 1 is connected to www through VDSL Line. 50 Mbit down, 10 Mbit up, trible play service.
The Provider is T-Online Germany.
Special notes for PPPoE: Dial in to vlan 7 with credentials for www and VoIP and Connection without credentials on VLan 8 for IPTV.

Now, how to set up following Site installation on Site 1:

Wan → Mikrotik → Lan, Port 1 should be connected to VDSL Modem, Port 2 and 3 should be in his own group and have to serve the Set Top boxes with IGMP enabled IPTV Multicast Traffic. Also there should be the same DHCP server as the other clients on the net. Gigabit 1 should be connected to uplink Switch for local Workgroup.

Because the WAN IP is dynamic, but have to have also a VPN connection to Side 2, there have to be an update to DynDns or so.
Also on Site is the VoIP Server, this one is the PBX for Site 1 and have connected the phone over ethernet to him.

Site 2 Installation:

Site 2 have cable acces to the internet with dynamic IP. On this Site the router above mentioned is installed an have to connect the internet. Then it have to serve this side with it´s own IP Subnet and own wifi.

Sub site 2 installation:

The Router Mentioned above is connected to the router on Site 2 via Ethernet, but have to serve a different subnet, WiFi net and also is the destination net for VoIP on Site 1 but have also serve VoIP from Sub Site 2 to Site 1 for Interconnection over VPN.

So basically I need a VPN connection between site 1 and sub site 2 which have to transport in QoS VoIP and some basic IP protocols for Maintainance purposes.

Now what would be the best practice to set this up?

Thanks in future for ur kindly help.