I'm having to apply some guesswork here!
If you're self-employed you don't normally need to get anyone to assist you with your annual tax return. You simply register for a Government Gateway account (which is a tedious process but not a difficult one) and then complete your tax return online. It's a remarkably simple process because, unlike paper returns, you don't see lots of questions which don't apply to you; you only have to answer ones which are relevant.
If you'll be running a business where you could end up with lots of debts if, say, someone you worked for went bust and didn't pay you then you really ought to run it as a limited company. By doing so, the worst that could happen would be that your business would be forced in liquidation (with your personal finances unaffected). If you operated simply as a sole trader you'd have to pay those debts yourself, possibly forcing you into bankruptcy and/or losing your home.
I can't see how running a limited company could be seen as 'scammy' or 'smacking of fraud'. Many people like to see 'Ltd' after a company name, as they see it as somehow 'more professional'.
However running a limited company does involve additional paperwork and you might need an accountant to help you with your returns to Companies House.
If I've misunderstood your post, please provide further information in order that I (and others here) might make sense of it!