chip select for the sd card is on pin 4 and on the octows page it says "do not use" is there a workaround possible ?
I don't think there is one. What would you need it for ?
Both boards work, but the larger WIZ820+SD one fits directly on top (or below) Teensy 3.1, so it's a lot simpler to make the right connections.
If you only want the SD card on the WIZ820+SD, you must connect six pins: VIN, GND, 4, 11, 12, 13.