myson velaire oil fired pressure jet boiler 70/90?

Hi there, I am currently re plumbing my central heating system which had a leak somewhere which is currently gravity fed, and i am putting in a pressure system as I want the header tank out, but i cannot afford the new boiler just yet, so my question is can I connect my new radiators to the oild boiler. Will I have to put in a pressure vessel in. I know that i will have to put in a filling loop. I have a feeling the boiler wont take any pressure at all.
Many thanks
chris