If your going with a traditional rads system id go with oil.
I have LPG coupled with underfloor heating. Gas boilers are supposed to be more efficient for underfloor than oil but cost wise im not sure.
Positives
Its cleaner burning and no smell of kerosene around the house.
Boiler is indoors, so less heat loss between the boiler and hotpress area.
Servicing seems easier and again almost no smell.
Gives you the option of gas appliances eg cooker, hob, fire
Negatives;
Its a gas system so you have to get an RGI plumber to install/work on gas. I was looking for a plug and play part for my boiler this year and most wholesalers would not even give me a price without an RGI number.
There are only 2 gas suppliers in Ireland: Calor or Flogas.
If you buy your own tank outright, you can choose between them for each fill.
However, the more common option is to rent the tank. But you're then tied to that supplier for a contract term, and until you change the tank!. The only upfront cost is you have to put in a concrete slab for the tank to be placed on. The supplier is responsible for the maintenance of tank, and insurance.
That said my neighbour has LPG too and would never go back oil, simply because its cleaner. Same person took out the solid fuel as he was sick of the bog and ash dust in the house.