Hard line will cost you a fortune in fittings dude. There are no hard line fittings that are cheap. You would be better suited doing it with tubes and finding a deal on fittings.
Note anything I link you to will be from overseas. Everything in the UK is a joke for prices.. Unless you find a sale.
First up pump.
http://www.ebay.co.uk/itm/331686925931?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
It's G 1/4 so compliant with most res/loops. It has a ceramic shaft and hauls some ass with water. Be careful when you prime it though, as it's kinda deep inside and will act funny if it's not primed properly. Most people use them fitted to a barrel/tube res but you can use others.
For the res.
http://www.ebay.co.uk/itm/60mm-Cyli...807770?hash=item211c7bfa1a:g:830AAOSwnHZYURNT
With that particular res you can use a G 1/4 coupler and literally screw it straight into the pump.
You can use this too.
http://www.ebay.co.uk/itm/200ml-Acr...825930?hash=item4b009cd74a:g:BFgAAOSwdj9XTvlb
If you want to save more cash.
For the water block.
http://www.ebay.co.uk/itm/NEW-Water...283904?hash=item2c9fe71a40:g:ZNwAAOSwyQtVzDZx
For the radiator... I would not advise using any cheap rad. Make sure what you get is copper, or at least purporting to be copper. I recommend using a Mayhem for £33.
https://mayhems.co.uk/radiators/mayhems-havoc-360-mm-radiator/
OK fittings. These vary wildly, however wait and buy them all at once and buy more than you think you need. For example a quick look brought me to these.
https://www.overclockers.co.uk/monsoon-chain-gun-fitting-1-2-x-3-4-multi-pack-blue-wc-195-mo.html
That's a four pack on sale, they are usually that much each. You could probably get away with three packs or so.
You may need to take the loop 90', so again make sure you plan well and prepare well. Those Chainguns may not fit straight into the CPU block side by side, so you may need to go 45' also.
Believe me, the planning is in the hose type/thickness and the fittings. The rest is easy, but you would need to find a sale on that day and order your hose/fittings at once.
Due to not skimping on the rad or fittings (the two main culprits for leaking) it still won't be "cheap" but you should end up right around a smaller AIO and spank it for cooling and noise.
The cheap loop I did comprised of fittings that were all in the sale (four packs of Chainguns and some £1 fittings I got from WCUK) with a cheap pump, second hand EK block and a 240mm Water Cool Heat Exchanger I got for £45 in the sale. It came to around £110 total.
For coolant I use XSPC as it has no glycol in it and so far has remained nice and clear and red.
You could always pick up a second hand rad etc. They don't fetch much used.