Hi,
my suggestion would be to use VPN rather than proxy. If you need a sporadic connection use your mobile/tablet and something like TunnelBear VPN (500mb free per month). Connect your device to any data (mobile data or wifi) use Tunnelbear app and enable wireless hotspot. Kobo connects to this hotspot and presents itself as connecting from the UK.
However if you need a permanent connection buy a VPN plan and any French telecoms compatible router. Set-up the device to connect to broadband/4G, provide VPN profile and you will be ready to go.
I personally use a Fritzbox! 7490 router which has multiple VPN profiles, DECT with SIP. I can connect to sites and look like I'm in my home country, and use foreign landline (SIP) in the UK.
Hope that helps,
Bart