I'm not an expert but I really don't think that if you simply register with revenue as a potential sole trader, that your benefit/allowance will be immediately stopped.
You can still receive jobseekers allowance/benefit if you are attempting to become self employed, as this is still considered to be seeking suitable employment.
As soon as you earn anything, or work at all (even unpaid), you loose your eligibility for the bog-standard jobseekers. However,before this if you visit your local job facilitator in the SW office (make an appointment) they can see what benefits you can keep when you earn up to a certain amount. It is called casual jobseekers allowance/benefit AFAIK.
Best of luck in your self employment!