Hi Conor100,
Great project! Let me give you some information, as you have mentioned some projects are not fully compatible with the Galileo the reason is they use instructions designed for other processors than the Quark, as example
TCCR2A, TCCR2B, OCR2A and TIMSK2 are macros designed for the Atmega as mentioned in the this walkthrough http://pulsesensor.myshopify.com/pages/pulse-sensor-amped-arduino-v1dot1 , you will have to search a workaround perhaps creating a function to obtain the same result , also we need to do the same for the interrupSetup() at this time this is not validated for the Galileo, see post https://communities.intel.com/message/218968.
Regards,