@Lee Ripma, any zip code that starts with 66xxx is on the Kansas side and anything that starts with 64xxx is on the Missouri side.
66101 is basically downtown Kansas City, KS. (not to be confused with downtown Kansas City, MO which is where most of what you know/hear about downtown Kansas City exists). All of the government buildings for KC, KS are in this zip code. The homes in this zip code will be older, around 100 years old or more. Most of this area will be risky. High cash flow (on paper at least). I would not try to flip in this zip code unless maybe if you are in one of the historical areas like Strawberry Hill.
66102 is further west of downtown KC, KS. The homes are generally newer than in 66101 (50-100 yrs old). This is a better area for SFR rentals but still not good for flips.
66104 - Same as 66102
64133 - Good rental area. Some potential for flips.
If you are interested in the KS side, 66103 is a very interesting area. Stick to areas south and east of SW Blvd. We have had lots of success with rentals and flips in this area.
Hope this helps.