110V/50Hz equipment in a 220V/60Hz country.

Hello,

I am living in the US, where I have
bought a couple of decent pieces
of high end equipment. I am considering
buying a couple more pieces, at a higher
price level, to upgrade my system, but have
the following problem: I am from Europe,
and there is a good chance I'll be
back in Europe in the next 2-4 years.

What are the acceptable options
regarding stereo equipment if I move,
apart from selling everything except
the dynamic speakers and starting
from scratch?

Given the difference in cycles,
is simply buying transformers
for voltage conversion
an acceptable option? Other options?

The equipment in question is
pre and power amp, SACD,
DVD-V and A, tuner.

Thank you!