I only discard the foreshots.
I collect my heads, hearts, and tails in separate glass mason jars.
8 liters is a little over 2 U.S. gallons
A 2 gallon run with a starting alcohol of 10%, a final proof of 100, and a collection efficiency of 85% will yield 5.44 US cups of alcohol or 1.3 liters of total product.
always ditch the foreshots-
2 gallon batch – discard the first 1 1/2 shot glasses worth
In terms of making cuts this is a good guide: http://www.clawhammersupply.com/blogs/moonshine-still-blog/12206385-making-moonshine-the-dummies-guide