Best rates & terms & you get to learn how to be a landlord with another unit besides you.If a newer investor can't go that route for whatever reason, then i would recommend just a standard investment loan from a local credit union.

Not sure where you are, but there is a credit union near me that I have gotten a HELOC with and they will do 100% LTV if it is your primary residence.

Call a big bank and a local credit union to discuss your options.

Like I always seem to run into issues when I talk to lenders about a portfolio loan.I would really like to somehow not do any projects for clients and just work on building my portfolio, I’m just not sure how to make the transition, two years ago I was 15 years into working as a union carpenter, I am honestly still trying to hit my stride with my business it’s doing well but I know I have more to learn and grow.

Both loans are with a small federal credit union that we’ve been doing business with for 30 years. 

There also may be local credit unions/banks in the local area that you are searching in that may offer products with lower down payments for both SFRs and 2-4 units, but I wouldn't know.

Find out if negotiation is possible - some lenders are more flexible to negotiating whilst others are too rigid (think national banks).Make 1/3 of your lender list federal credit unions.

We also have a HELOC through a credit union that is for 100K, interest only payments for 10 years if we use it with the ability to lock a rate. 

This is usually provided to you at a lower cost than a cash out refi through a local credit union, for example.

You can go FHA (3.5%) or look into credit unions and see if they offer any first time home buyers programs.