1900-2200 I would use for 5s. 2200 gets a bit over powered. I ran my 1515 1y (2200 kv nue) on 5s for a bit and found it over powered. 4s seems just right. but that was me, other may love that over powered feeling.

a 60mm medusa 2000 kv or neu 1512 in same range would be ideal motors for the buggy.