@David M.I should know better than to call them clients (since I am in class lol) - potential customers.

That's when states shut down short term rentals, and Airbnb refunded every customer's money, many arbitragers were in deep financial trouble. 

You could get the customers info, instead of giving them yours. 

They continue to farm out their products and their customer service keeps going downhill.

Spec homes are much easier, quicker and more profitable as what you are contemplating is basically a custom build process.All that being said there are some really successful strategies you can employ to ramp up the process and accomplish your goals. 

You can get customized search results emailed to you when you go on most brokerage’s sites, they’ll give you the option to save your search and get emails when there are properties that fit your parameters.  

I have found an overwhelmingly more active response when I text new deals to my customers vs just emailing them.

., You probably need some kind of Help Desk Software:"Help desk software is designed to provide a customer with information and support regarding a company’s products or services.

They provided great customer service and did an excellent job removing 3 large oak trees from my property.

If this is a more affluent clientele, I would see if you could get them to do auto-deposit from their checking accounts.The key to collections is to find the right fit with your customers so they pay on-time with anything but cash.