Artificial light can rarely imitate natural light. For color rendering, incandescent has always been the best, approaching 100. Typical fluorescent, for many years, has run in the 70's, with "improved" versions reaching the 80's. Specialty fluorescents were made to reach into the 90's. Most people find the 80 CRI fluorescents acceptable because they've been around for so long.
High Pressure Sodiums, the "yellow-ish" light that you see in parking lots is in the 40's. Metal Halide, the white-ish light that you see on roadways, inside factories, etc, is in the 60's.
LED's are not naturally white. They need to be corrected to be white. Most LED products are in the 80's. Only a very few are in the 90's, but newer technologies are making 90's more available. It cost more to make an LED into a 90, so you'll pay a little more. And because more correction is necessary, they are usually just a little less efficient.
Kelvin color has little to do with CRI. Ballasts can only affect CRI if they are not driving the lamp properly.
Of course, there's a lot of variations of all of the above figures. YMMV.
CD