Multifuel means you have to get rid of acidic coal ash, you can't just compost it, must be stored safely until cooled & then into the bin (more faff than wood ash which I think cools faster as well, i think). Ours is multifuel, but we'd never use coal. Might appeal to some, though.
Spend some time looking at steel vs. all cast iron too, they have different characteristics.
Look at vent features, they vary & some are easier to use than others.
Otherwise I'd see what a good installation company recommends.