Also, https://www.voipfone.co.uk/ works with 3CX and they offer national and mobile bundles. I've tried and tested these too along wit CallCentric but they're in the US. still works through, you just have to mess around modifying your outbound rules to prepend INT dial codes.
I'm glad with French providers, prices are cheaper and you are free to go. 3€ for a sip channel / month giving you 2 SC
unlimited package for french use including mobiles and some european countries 27€ / month