Zoning

The short answer

is yes -- but it is a little more complicated than it sounds.  It is essential, particularly, that both sides of any zone valves be dripped to a wet return (in principle you might get away with dripping only one side -- the upgradient side, whichever that is -- but I strongly recommend both sides).  Second, any zone valve which you use to zone low pressure (saturated) steam such as we use must be full port; very odd things can happen if you try to use a reduced port valve.



If you are sure your traps are all good, it isn't really necessary to zone dry returns, and wet returns should not be zoned.



Make sure you have adequate venting; you may need to install additional vents before any steam zone valves.



Have you considered using TRVs on the radiators in the spaces you want to have cooler?

Zoning your system

can be done no matter what fuel you burn. One does not depend on the other.



See Jamie's post for some good ideas.