Plugin(s) to handle Florida County Sales taxes

-- url of the page with the problem -- : safetyzonespecialists.com

My Florida based client charges state sales tax and a cumulative county sales tax on orders shipped to Florida.

I need a plugin or plugins to solve two problems.

- Tax by county
- County tax calculation

Possible solutions...

Tax by county
Add a dropdown of Florida counties that would appear for Florida based address entry. Have this field trigger the addition of Florida county tax based on Florida county tax zones. Tax rates vary based on county.

Tax calculation
Florida county sales taxes have a maximum cap for orders over $5000. For example, in a 1% tax rate county the tax is 1% on orders up to $5000. On taxes over $5000 the tax is $50 (1% 0f $5000). We need a max cap on the county tax calculations.

Note, the cap does not effect the FL state sales tax which is 6% of the order regardless of size.

Reviewing the Hikashop forums, county sales taxes have come up several times over the years. There is likely an opportunity here to sell these plugins to a number of users.