How do I get an agent to send me deals instead of MLS alerts

The 78 year old with six units isn't on the MLS and no agent is going to hand you that one on a first call. Those come from an agent's own list, and an agent gives their list to the buyer who already made them money.

So the sequence is backwards from what you want. Buy something ordinary from them first. Even a listed deal at a fair price where you close clean and don't renegotiate on day 14 over a $2,400 repair. That closing is the audition. After it, you're the name they think of when a seller calls them and says my knees are shot and I want out by spring.

Don't offer to pay up front. It reads as someone who doesn't understand how they get paid and most brokerages have no clean way to take it anyway. What you can offer that costs you nothing: tell them exactly what you'll pay for and what you won't, answer the phone, and give them a straight yes or no within a day. Agents complain constantly about investors who ask for twenty analyses and buy nothing.

On your four names, I'd keep the one who called back and add four more. One responsive agent is the whole relationship, the other three were never going to be it. And ask that one who else in town works with investors, because the good ones know each other.