Please suggest how and “what order” I should install Slackware, FreeBSD & Solaris on a p4 machine

I want to install Slackware 14.2, FreeBSD and Solaris 10 on a p4 machine but multiboot is not working as lilo overwrites grub and btx boot loader can’t detect others. I had to boot slackware and Solaris with the installation disc for a good number of times. I installed all boot loaders on MBR. The following is the partition layout on an IDE disc; /device/sda1 20G /dev/dsk/c0d0s0 20G /dev/ad0s1 20G Please suggest how and “what order” I should install these OSs