500k to 800k approximately
The easiest way to go about it would probably be using Home Equity in the form of a Secured Line of Credit; of course, you actually need to have a property with enough equity to do that.
Banks aren't going to lend out 500k to 800k without some form of security; and if you don't want to put your house up for collateral, then you would have to put assets of the business up as collateral.
What type of business is it? Does it have any physical assets?
Your typical schlep that works in the Bank Branch doesn't have the aptitude to do this sort of deal; you probably want a Commercial Account Manager. This is specialized lending.