If you get jewelers scales these are sensitive enough to measure the weight of 1cm worth of the paste...
I calculated 1cm to be roughly 0.3 grams of paste.
Ive been using both - the Solos are essentially the same (if you get the same colour as the tubes) but some are slightly different.
They work in the same way but are harder to mix as you can’t measure the mixtures on a card (as you do for the zenicolor5) you need to do it by weight instead and...
Providing you use the same melt and pour base (just a clear and white version) most of the assessment companies treat it as the same - the only difference with the white is that it contains the white colourant pre mixed - you can do the same by just adding titanium dioxide to the clear base to...
Just a heads up, some of the providers of CPSRs will allow you to use a mix of Clear and White M&P base providing it's the same brand/type of base - worth checking with whoever your planning to use.