You would qualify for entrepreneurs' relief if you could sell your shares in the limited company assuming you will have run it as a restaurant and not just let the property or business to someone else to run. If you qualified for entrepreneurs' relief, you would pay Capital Gains Tax at 10% if the CGT rules as they are now are the same at the time you are ready to sell up. Clearly, the terms and length of the lease would have an influence on the value of your business.
Another way to get entrepreneur's relief as opposed to selling your shares in the limited company would be to put the business through a formal liquidation and then make a capital distribution and claim ER on the gain. Take a look at the notes on entrepreneurs' relief here
If you simply roll up post corporation tax profits at £300,000 per annum, paying that out as a dividend in one tax year would leave you with a huge higher rate tax liability of the order of £536,000 at today's tax rates. Take a look at the notes on dividends and tax here
. It would make far more sense to make dividend payments annually to use the lower tax rates.
Whilst high salaries are costly in terms of tax and national insurance contributions , another option would be to set up a pension scheme for yourself though you could not access the funds until you reached the age of 55 at the earliest. There are, however limits on the value of pension funds beyond which they become tax inefficient. The limit is about to be reduced to £1.4 million.
You could also reinvest some or all of the proceeds of the sale of the business into new business assets, thereby deferring some or all of the CGT you would otherwise pay under the business asset rollover relief rules. You can read about those here
You really ought to seek out some face to face advice with an accountant specialising in business planning who can take a look at the business in detail with a view to making recommendations as I can really only give you a few pointers in a place such as this site.
I hope this helps but let me know if you have any further questions.