I have 2 JBL D140's reconed with RCF 4ohm kits wired in series in my 215 and both of my single 15 cabinets, a Sunn 115Bh with a Utah and a BFI with a JBL 2220A as 8 ohms. I also have my small 8" JBL 2118H as an 8 ohm. With this setup, I can use any combination of 2 cabinets with my 200s. You would have to make sure your amp is wired for 16 and 8 ohms to use any other combination and using a 4 ohm cabinet with any other cabinet will drop your impedance down to an unusable point unless you are using a solid state Sunn which can go to 2 ohms.
It is usually easier to find 16 ohm speakers rthese days than 4 ohms. I see 2220J's on Ebay sometimes. Look in Pro Audio