The investment premium of an ARF must come from a pension/PRSA policy.
If you have a personal pension/PRSA/AVC/are a propriety director, then you would be able to invest some of your pension scheme proceeds (after a tax free lump sum) in an ARF (subject to certain criteria). Yes, withdrawals from an ARF will be subject to PAYE, but you can allocate some or all of your Standard Rate band & tax credits to this income.
If you do qualify for an ARF, but decide to take the proceeds as a lump sum, it will be subject to PAYE - so you will have a lot less to invest in in your straight deposit account.