Pay Monthly Sim Only?

dafunk06

Hi,

I would like a pay monthly sim only contract for the purposes of making european calls.
There seems to be two routes to go:
High minutes and use a call forwarding number that would be inclusive of minutes
Or
An offer that has inclusive/unlimited landline minutes and then use a landline call forwarding operator (i.e. the post office) and pay their call forwarding costs.

The latter option would be safest but I am having trouble finding operators which provide bundled landline minutes on sim only. Orange does this but I would rather not be with them.
Any recommendations or alternative solutions?
I make a lot of calls to Europe over the monthly period and it must be a 30 day/1 month contract only.

Thanks in advance