Is there a publicly available list of equity gap investors for first-time, self-funded searchers?

For those equity investors that invest in self-funded search deals, what are your preferences as far as building relationships with searchers ahead of time / seeing deal flow pre-LOI?

What are best practices for pre-LOI deal protection mechanisms to ensure appropriate alignment of interests between the search and equity gap investors (i.e., when marketing deals prior to exclusivity, how do you protect against others approaching the seller and offering a better price, etc.)?