Thanks for the quick replies!
I figured out that the checksum I was using wasn't right. Running the ser.write('$PMTK....') in the python shell returned the right checksum, changing the checksum fixed the problem!
For others with the same problem: for RMCAonly I used: '$PMTK314,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*57\r\n'
and for the 10hz update rate: '$PMTK220,100*17\r\n'
Thanks again and I am definitely gonna get some inspiration from the codes in Abbadabbatech bitbucket! Great job!