Does the new iMac have SD Card reader?

All current iMacs are SSD based. You can buy up to 8TB of SSD storage on the 27" models.

Regarding a SD reader if you are considering a 24" no the case is too narrow to make one fit. However you can buy either an external dock from www.macsales.com that has one among other ports or you buy a stand alone external SD card read which is very inexpensive.

The 24-inch iMac does not. The 27-inch iMac does.