R4 DS / R4DS is the First Slot-1 Flash Card for NDS And NDS Lite, the Lastet kernel is V1.18.

The R4 DS Not support SDHC Memory Card and not support DSi, For R4 DS Card Support SDHC Card to 32GB Please see R4 SDHC, R4 SDHC V2.10T, R4 Ultra and For R4 DS support DSi please see R4i Gold or R4i SDHC.

You can buy R4 DS and R4DS Combo in Store, Just follow below links::
R4 DS and R4DS + Kingston 2GB Card

Kernel Download Links:

R4 DS English V1.18 kernel
R4 DS French V1.18 kernel

Don't know how to install the Kernel, Just follow this R4DS Guide.

Most of R4 DS user Use Wood R4 Kernel after Yellow Wood Goblin released his brand new firmware, Wood R4  v1.04, You can download the Wood R4 V1.07 instead this R4 DS V1.18 Kernel