GRUB2 (the GRand Unified Bootloader) is a multiboot boot loader.

If you want to set the size of gfxterm font, then specify 
FONT_SIZE=size in the build options.  The default size is 19.

If you want to install grub2 on GPT, you need to put a BIOS boot 
partition on GPT.  To install it in the MBR replacing lilo, generate 
a config file in /boot/grub and launch grub-install, e.g.

mkdir /boot/grub
grub-mkconfig -o /boot/grub/grub.cfg
grub-install /dev/sda