Help for VPN on RouterOS

Qnewbie

Planning to place RB450G as server in HK, one RB750 in mainland China and one RB750 aboard.

Since I haven't any experience in VPN, detailed help required and highly appreciated:
1. OpenVPN or IPsec?
2. Three site should be within the same VLAN.
3. Site-to-site from aboard/mainland to HK.

Thanks!

Qnewbie

For RouterOS, RB750G costs less than HK$500 and has power consumption of a few Watts. It is definitely great for passing through GFW.

I set up PPTP vpn according to the following link:
http://wordpress.wlevels.nl/configuring-routeros-as-pptp-server/

Hence my android phone can use as ip-phone.