This is an update of the 4-way I have in my A1200D, it has 2 44 pin headers, and 2 40 pin headers.
One of the 44 pin headers takes the ide cable from the Amiga motherboard, the other 44 pin header takes an ide cable to your existing 2.5" HDD. (You'll need another 44 pin Ide cable)
That leaves you 2 40 pin headers for standard IDE cables to 3.5" HDDs and normal CD-ROMs.
The card itself takes power from the power lines of the 44 pin ide cable on the Amiga motherboard.
-Jar.