um, no to the restrictions there, but the real 'apple to shoot for' is the ability it would give us to be able to raise serious amounts of money. People, and more importantly Companies, will make donations to a "Charity" where they won't to a "Company Limited by guarantee". Indeed, it is *all* in the name.
The HMRC thing should be sufficient for starters. Some large donors may like full registration before they donate, but I think most just want to know it's tax deductible.
What do mean by "no to the restrictions"? There are all kinds of restrictions on charities that there aren't on other companies limited by guarantee. The board of a charity are trusted with donated funds, the board of a plain limited company are just trusted with the company's funds - that's a big difference.