Buyer used conventional financing - 25% down.

Do you have an conventional lenders that you recommend that are have experience with properties with ADUs?

Business StructureWe want to run the business through an LLC for its benefits.We are taking a Conventional Loan in my name to pay for the property.

You'll never cash flow with any kind of conventional financing in place.

Is 5% just a normal conventional loan?

Conventional, 5% down because of owner occupancy.

I am doing a conventional loan with 20% down. 

So put together a nice, very informative, written plan that describes the property, the deal, the financing needed, the returns, how you will manage it, your team, etc, and take this to them and ask to discuss their lending options.If, on the other hand, you are flexible on not using the LLC at first, then you can probably more easily get a conventional loan to purchase the property directly in your own name. 

If you currently have an FHA loan then you'll not be able to take advantage of the 3.5% down FHA loan in the same market, but there are several loan products that offer something like a 5% down loan (which is a conventional loan product).  

This is not an issue for SFH + ADU, but if you add an ADU to a multiunit, conventional loans are off limits and you must consider non-conventional or commercial loans for refinance.