I run an ISP with a lot of rural users. Here is my two cents from my experience:
1. There is no issue with VDSL back haul. Copper backhaul is an ADSL1 issue and I have no clients on ADSL1 and its hardly a thing anymore, thank goodness.
2. I would generally pick VDSL if its available and this is quite often the case now. I have clients with sub-10Mbps connection speeds who are getting VDSL. This is because its a better protocol.
3. If your connection speed is at the low end it will likely work but don't expect it to be solid. I am seeing daily reconnects with my clients at the marginal end.
4. To give it your best shot get equipment which supports G.vector and G.INP. My go to combo is a Draytek DV130 (running 220.127.116.11 firmware!) and a Mikrotik - usually hAPac2 but am just about to start deploying hAPac3's. Anything cheap or Netcomm is a pain in the proverbial.
5. Whether you choose VDSL or wireless is up to you. There are pros and cons with both. Keep in mind RBI could also be an option.
I hope this helps.