Kitchen remodel with shaker cabinets and granite countertops was about 4K (pretty small approx 12 linear ft of top and bottom cabinets with sink/fixture cutouts.

Cabinet beds should hold up better. 

Also the house is completely gutted out, do I install the cabinets first or kitchen floor?

Our large 1 bedroom 1 bath & 2 bedroom 1 bath apartments have spacious living rooms with large picture windows, cozy kitchens with lots of cabinet space, dining areas, hall closets with plenty of additional space, bathrooms with vanity, tub/showers, wood floors and large bedrooms with wall-to-wall closet space.

A flipper will typically do all new cabinets, quartz countertops, stainless steel appliances, while a rental buyer may just change something out if it's really old or broken.

Even though I gutted the kitchen we are going to use corian and shaker cabinets that are wood color.

I always tell clients do basic updates line new cabinets, sink, stone counters, paint and this can get you a large rent increase plus hopefully some equity.For financing there is a 10% down option that gets you around the self sufficiency test via a local credit union or FHA is popular for the legal 2 units. 

Mold, rotten MDF, crappy repairs to get the cabinets to "look" ok, all of it behind cabinets, appliances, and generally all covered up with the thin cabinet siding you can buy at HD or Lowes.It was apparent to me that there had been some sort of significant water event, but I could not prove the seller was aware; however, a few days later, I was chatting with a neighbor, and she asked if I was aware of the flood that had occurred in the property. 

The house ended up with brown tile, brown cabinets, brown countertops, and a shade of brown paint that looked more yellow than it did brown.To my credit, that color palate was more popular at the time, but when I look back at it today it's a bit embarrassing.Going forward I have worked with designers almost ever time.

minor cosmetic updates: landscaping, painting, cabinet hardware, update light fixtures.