Hello.
I don't know if it's the cheapest way to tune up your engine.
I can tell you where some parts are from.
You need to make some parts by yourself, they aren't all in stock.
The pulley on the crankshaft is from early injected fire engine, for exemple old fiat punto 55.
The pulley on the alternators is from alfa 33 water pump.
the resti is home made,customized.
If you can do it by yourself maybe you can get a poly v kit for little money.
Mind! There is no centrifugal anymore so if you want to use that parts you must add an external oil filter.
You can find poly v kit for 500-126 with or without trigger wheel.
People use centrifugal and poly v taking pulley from injected cars.
I don't know where to find parts, I think from fiat too.
Maybe from 899 i.e. or later fire enginw like 1.2...
I don't know but I saw.
Look at this video:
http://www.youtube.com/watch?v=9QxbrwFis_wBye.