In your case I would go for a 2 line Obi 202 voip adapter ( US $ 75.-) and voip.ms for the first line and Localphone.com for the second line( international calling) . If you are a heavy user you could take Voxbeam instead of Localphone. Like some people mentioned, 'Eastern Europe" is very vague.
the PAP2T is the one I'm using and I love it as it's has two phone ports unlike the Obi that only has one or at least the models I've seen only have one port.
So setting up two lines on the same device is nice as in the future I'll need a business number. Now yeah you would have to pay for a number for that port from voip.ms if you want two lines. If you can find one for a good price I've no issue it's been good to me.
I think it's worth pointing out that once you're setup for VoIP/SIP, you'll be able to call others who are setup likewise for free via SIP. Plus, for example, if you have an OBi and the one or two parties you talk to most in other countries also have an OBi, then you could call each other for free using the OBi numbers of each device. The point is you won't be limited to using just PSTN numbers, which could save you some expense--a little or a lot.