Most, if not all providers will classify a twin pregnancy high risk.
I am sure there may be birth centers that take twin births, but I have not heard of one.
Here in the UK, because you cannot get "fired" from care, you can just tell them you WILL be having a twin homebirth. In the US is not so, unless you hire a private midwife who is comfortable with attentind twin home births.
One concern with twin pregnancies is the risk for TTTS (I lost twins at 18 weeks because of that) so it is important to check if the babies are identic or not, and then have more ultrasounds throughout the pregnancy to monitor amniotic flui levels, growth discrepancies, etc.
Also there is a increased risk (not sure whether it is a small or big increase) for cord prolapse after the vagi birth of the first twin.
There are other things to consider, too.
Having said all that, you can read story after story of wonderful twin homebirths, as well as natural birth center and hospital births on these boards!
I am a homebirther who hates hospitals. Yet, with my sad experience with a twin pregnancy, though it was very rare, I would personally request through medical monitoring and a hospital birth if I ever were to be pregnant with twins again.