The units are ready, but due a personal situation I only want one.

-If its a large house that has a dedicated laundry room on the first floor, throw in stackable  laundry units on the bedroom floor.

I've got a long term tenant lined up & the unit is a non smoking unit, which the applicant is aware & fine with for indoor.

First recognize that 2 to 4 units are valued on comps and not cap rate.  

Looking to invest in multifamily apartment complexes>50 units.

I will be living in the guest house, while renting out the main.Both units are without washer and dryer units, my question is, do I supply them in the main house; or let potential tenants figure that one out?

The best way to do this is to renovate a unit or two to the specifications to bring it up to market.  

For path #2, you mean purchase & renovate a 3-5 unit building right?

I house hacked this 4-unit property start year of 2022, moved out in a triplex in 2023.

If you really want to get rid of them, sweeten the pot by offering to return their deposit after you verify the unit is empty with no damages.