multi-boot linux with esxi (one ssd, one hdd)

[carrot.papaya]

well, it is not practical to multi-boot a server for virtualization.
but for me, it would be just for educational and testing purposes.
i would like to try different virtualization hypervisor without changing hard disk or keep installing and uninstalling.

currently i have esxi hypervisor 5.1 installed in my ssd, and all VM files in hdd. what I have in my mind is to be able to multi-boot Fedora with ovirt, Proxmox (debian), OpenNode(RH or CentOS) and ESXi.

so bootloader for Fedora, CentOS, Debian are the same Grub while for ESXi it is syslinux.

My only experince with multi-boot is dual boot my laptop with Ubuntu and Windows. So I'm pretty noob.

1) May I know in which order should I install first?
ESXi then linux?

2) May I know how should I partition my storage?
my initial thinking is partition my 60GB SSD to 4 partition, one for each bare metal hypervisor.
same goes to my 1.5TB hdd (not too sure If I need to)

I found this blog which has a lot of info about multi-boot. I'm trying to follow it while try to get some views and opinions from here
Highly Unsupported: Multiboot ESXi 5, Windows 2008 R2, RHEL 6, XenServer 6

Thanks

Appreciate your time.