The Balance One has both a PPTP and L2TP server built in; you don’t need your tomato router if you are setting up remote access. I have used both VPN servers with remote Windows, macOS*, iOS* and Android clients using the OS’s built-in VPN client software. I recommend using L2TP over PPTP for better security.
*macOS and iOS no longer support PPTP, so should you have any macOS or iOS users now or in the future, you will have to switch to L2TP to support them (not to mention the noted security implications).
Here is a nice write up on setting up and configuring the L2TP server on the Balance: Setting up L2TP With IPsec. To setup the PPTP server instead, select PPTP in place of L2TP.