What are some devices that i could use to replace several TZ series devices. The only function i really need is the Site-to-Site VPN. Preferably not a Sonicwall device they have the worst support I ever came across.
Take a look at Astaro Security Gateway. They have a line of products which will serve as firewall as well as a VPN gateway. They also have a remote-office zero-configuration site-to-site VPN device which looks really nice. I use their firewall product (ASG220) in our data center (a pair of them in a HA configuration) and have had good success with them over the last few years.