Running two LP heaters

A quick search shows me most ceiling-mounted shop heaters are probably all 240V, so unless that plug also is, you'll need to run new electrical. I had a heater that looked something like the one below at a place I used to work, and it worked decently well.

Here's a nice heater sizing chart to help decide how powerful a heater you need.

I understand your dilemma. I have a few comments about using heated water from a wood stove to circulate in a radiator. The concept seems simple, however using a circulator pump also requires a control panel of some sort, unless you intend to let it run continuously and manually switch it on and off. This task is normally controlled by a thermostat and control board. The pumps usually run on low voltage supplied through the control board. Using line voltage (240VAC in most of Europe) and an in line full voltage thermostat would be very dangerous. Another concern would be protecting the circulating water loop from an over pressure condition. Heating water above the boiling point would be a major hazard. You would need a pressure relief valve and a way to shunt water away from the heat exchanger if the wood fire overheats the water. Another limiting factor would be that this heat source would only be available when the wood stove was burning. Perhaps you might consider an infrared quartz space heater instead of the oil filled radiator. These heaters are extremely efficient, cost a fraction to run compared to traditional electric heaters.They come in a variety of styles and shapes. The cost of these heaters start around $80.00 USD to a high of $500.00 USD depending on how large and fancy a unit you select. They do not require special wiring and have a fairly low electrical draw plugged into any standard outlet. Infrared heaters work by heating objects via infrared energy as opposed to heating and distributing air. The heat in the space is usually very even and comfortable. Check out what is available in your area.