I have existing Insteon switches. Can I use them with Vera Lite?
Yes, but you need an Insteon PLM such as:
http://www.smarthome.com/2413S/PowerLinc-Modem-INSTEON-Serial-Interface-Dual-Band/p.aspx
also, look here for more info:
http://www.smarthome.com/2413S/PowerLinc-Modem-INSTEON-Serial-Interface-Dual-Band/p.aspx
Can you know powerlinc modem for Europe?