there is no license limitations on site-to-site VPN connections. The license limitation is regarding VPN clients (dynamic vpn). You get 2 concurrent connections included in the base system and can purchase extra if needed. In your setup I don't expect that to be a problem 🙂
You can possible use openvpn on Linux to emulate a site-to-site connection and Pulse Secure (the client used for dynamic VPN) can be found in a Linux version.
I hope this answers your questions.
Ah that is great to know 🙂
Which would be a better box to use as I see both the SRX240 and SRX300 close in pricing on ebay...
though I like the fact theSRX300 comes with 2 SFP slots...
Think the SRX240 won't support JunOS higher than 12.1?
The SRX240 platform has been announced end of life so no new features will show up. Buying a SFP-module for the SRX240 will be very pricy as well so I would recommend looking at the SRX300 - and as a lab/test firewall it is good that the SRX300 is fanless 🙂
Please note that you cannot buy support when buying second hand and that way get the latest software updates for the SRX300... and you need the latest version to get a stable platform as the initial releases was quite buggy 🙂