An IFA (Independent Financial Advisor, not Institute of Financial Accountants!) will give you financial advice and potentially set up certain investments for you. They are regulated by the FCA in terms of what types of products they are permitted to advise on; anyone who is not regulated as a Financial Advisor (Independent or otherwise) may only offer INFORMATION, not ADVICE.
An accountant is a more general term for someone who will actually complete paperwork (whether that be company accounts, personal tax returns, whatever) and help with questions about your existing situation. They will generally not be permitted to offer advice on which investment products to choose for a new investment.
Of course some accountancy firms may offer both types of service. It sounds as though the one you are looking at doesn't offer what you need, but you could always ask - as they are so heavily regulated by the FCA they will have to tell you if they can't provide what you are asking for!
The Money Advice Service has advice on choosing an advisor:
unbiased.co.uk has an overview of the different types of professional help: