There’s even a header for SPI making it easier to add custom hardware if necessary. This is a dual-layer board which may not be ideal for your own fabrication process. [Bert Kruger] posted ...

The chip expects 3.3 V logic so he made use of a MC74LVX50 hex buffer to tailor the Arduino’s 5 V. Currently he’s working on revision two of the shield, which will include SPI flash memory.

Then, an Arduino board might be exactly what you ... module since they connect to different pins (the Wi-Fi shield to the SPI bus, and the Bluetooth module to the TX and RX pins).