To get a Class III weapon you first find the one you want and buy it.
Some states will forbid you to own one. Go here to see...
Your dealer will help you fill out the paperwork to send to the ATF to pay your $200 tax. This is what you need to actually take possession. You own it but cannot take it home till the tax is paid.
If you have a corporation...you can skip the CLEO signature and photo requirement. Otherwise... you will need to have the Chief or Sheriff sign off after checking you out.
Send it in with a copy of your prints and wait.
I have a corporation Mine was approved in 15 days.
Price will be high so expect to pay several thousands for it.
Here are the average prices....