Most Profitable: How to build a Ethereum ETH mining rig for less than £1300!

I have built 5 rigs now and counting. I have tried a variety of combinations, NVIDIA Chipsets for Lyra algo and the likes, but the most bang for your buck so far is Ether Mining Rigs.

Here is a list of hardware and Cost Estimate for each to order from Amazon, UK
I assume some basic knowledge of Windows Management - so hope it comes as a given than Operating System - Windows 7 is to be installed.

This post is all about components necessary to build a full featured Mining rig, primarily from Hardware ordering perspective.

ETHER MINING RIG Building - UK
What computer parts you need to build a 100Mh/s Ether Mining Rig

Hardware

4 x RX470 8GB cards http://amzn.to/2qxrpw8

Current Price Estimate £940
1 x H81 Motherboard http://amzn.to/2qtSOBk
£55
1 x Intel CPU http://amzn.to/2rsj9NW
£45
1 x 8GB DDR3 RAM http://amzn.to/2rslpEV
£45
1 x 120GB SSD http://amzn.to/2rs5NRL
£55
4 x PCI x8 Riser http://amzn.to/2qxtDM9
£35
1 x 850w PSU http://amzn.to/2qsH0yw
£115
1 x 50L Storage Box (stick motherboard inside, GPU on top) http://amzn.to/2qT5jYb
£10
Total Cost estimated £1300
You can try cut corners here and there, PSU could be Corsair, but in my humble opinion EVGA is better, but there you have it.

With today's Ether Prices; cryptocompare.com ETH mining Calculator estimates this 100Mh/s Rig, will result in $300/month a month.

Software: TODO

Windows 7 - buy/student/trial/re-use existing license - your own cost

AMD Drivers + system drivers: Drivers needed for graphics card and component

Nicehash Miner/Guiminer