There's no problem in using an RF tank stat - but I haven't come across
any
RF zone valves with remote motor controls and volt-free contacts - which
is
what you would need to avoid having to run cables to it.

What about using a RF tank stat, and a seperate wired stat and zone valve
locally on the cylinder.

At the preset temp the wired stat could close the zone valve, and the RF
stat report back to the boiler to switch off.

By using two stats you may have a slight difference in switching temps
(which may cause a little bit of cycling) but it should work ok.