I don't recommend changing the Partition sizes from the defaults, as I consider them 'Perfect'. The only real difference between MBR and GPT is the MSR Partition for UEFI GPT layout
SYSTEM - 260MB | GPT MSR 16MB | WINDOWS - REMAINDER | RECOVERY - 990MB
And when I say 'Perfect', this layout mirroring between MBR and GPR allows you to convert from MBR to GPR without moving around any partition data