Sam, I've used IHC for Short-Term since 2006. They are pleasant to work with, and most importantly, pay claims without a lot of B.S.. Lots plans to choose from. Premiums are monthly, or get a big discount if all months paid up-front.
Accident Insurance and critical illness insurance can be offered in the same app, adding ancillary waives the $20/month network fee so it's an easy sale.
Contact me for the best contracts in the country, my agency originated from their marketing team.
6 mth advances available.
Edit: There is also a guaranteed issue version of the plan available in many states. The plan is identical however the coverage amount is $250k maximum instead of $2,000,000 and the client also only gets two free office visits, not three.