We are going to achieve 2 things here.
1. Install the OpenVZ OS
2. Install Ruby 1.8
3. Install the OpenVZ Web Panel

Install the OpenVZ OS

1. Get the ISO from https://download.openvz.org/virtuozzo/releases/7.0/x86_64/iso/
2. Install it as usual

Install Ruby 1.8

[[email protected]]#command curl -sSL https://rvm.io/mpapis.asc | gpg2 --import -
[[email protected]]#\curl -sSL https://get.rvm.io | bash -s stable

Logout or restart ssh session

[[email protected]]#rvm install 1.8.7

Install the OpenVZ Web Panel

1. SSH to OpenVZ
2. Download OpenVZ Web Panel from github then unzip it

[[email protected] ~]# wget https://github.com/sibprogrammer/owp/archive/master.zip
[[email protected] ~]# unzip master.zip

3. Install the script and ruby dependencies

[[email protected] ~]# cd owp-master/installer/
[[email protected] installer]# chmod 777 ai.sh
[[email protected] installer]# ./ai.sh

4. Access the Web Panel
login with admin/admin

1. To build white box for running ESXi
2. Support up to 64GB DDR4
3. Total power consumption below 30 watt on idle
4. Expandable, with PCI expansion slots and multiple SATA ports
5. Cheap as possible

Part lists (as of October 2017)
Intel – Pentium G4560 3.5GHz Dual-Core Processor RM 320.00 (Lazada)
-poor-man’s Core i7 CPU, price vs performance, when it introduced it cannibalized the i3 sales. Intel realized this and slow down the production. Low TDP.

Asus – PRIME B250M-A Micro ATX LGA1151 Motherboard RM 415.00 (Lazada)
-4 DIMM slots and support up to 64GB DDR4. Alternatively, you may consider Gigabyte GA-B250M-D3H.

Avexir Core Series DDR4/2400Mhz/16GB/LED RAM RM 569.00 (Lazada)
Avexir Core Series DDR4/2400Mhz/16GB/LED RAM RM 519.00 (Lazada)
-simply because it is the cheapest. 2x16GB is cheaper than 4X8GB RAM. Furthermore, I have 2 more free DIMMs slots with this configuration.

Corsair – VS 450W ATX Power Supply RM 148.00 (Lelong)
-better than stock PSU

Tecware Quad Mini Cube ATX Case RM 180.00 (Lazada)
-cheap and affordable, importantly it perfectly fit my IKEA rack for space-saving purpose. The size and dimension are resemble the infamous HP Microserver Gen8 (bought it for a year ago then sold it because underutilized, now feeling regretted :P)

Western Digital – Caviar Blue 1TB 3.5″ 7200RPM Internal Hard Drive (Re-Use)

I bought mostly from Lazada due to stock availability and abusing their 10% voucher (price listed above before 10% discount). Price for CPU and RAM is higher due to scarcity and exchange rate.

Power Consumption
Average on 29 watts!!

ESXi running VMs

Step 1: Install ESXi PowerShell Module
Run PowerShell with elevated privilege (run as administrator)

PS D:\> Install-Module -Name PowerShellGet -Force
PS D:\> Install-Module -Name VMware.PowerCLI

Step 2: Changing the Windows PowerShell Script Execution Policy

PS D:\Set-ExecutionPolicy Unrestricted

Step 3: Download ESXi-Customizer-PS
Go to https://www.v-front.de/p/esxi-customizer-ps.html and download ESXi-Customizer-PS-v2.5.1.ps1 and move the script to D:\ (to ease our job)

Step 4: Run PowerShell script

PS D:\> .\ESXi-Customizer-PS-v2.5.1.ps1 -vft -load net55-r8168

net55-r8168 is the package name from https://vibsdepot.v-front.de/wiki/index.php/List_of_currently_available_ESXi_packages containing Realtek NICs driver.
PS D:>.\ESXi-Customizer-PS-v2.5.1.ps1 -help for more customization