Pea Gravel (Natural Gravel) Aggregate

It sounds like river gravel and you can buy it in many different sizes at the landscape supplier. You can also get different 'roundness' (ie how round or angular the rocks are) and will generally pay more for rounder rocks. The colour will vary depending on which river the stone came from.

Much the same as the previous post, it will be rounded gravel which typically means river gravel. What is more important it will have been run through a screen and graded to a particular size. The American site may give it as 1/8", 1/4", 3/8" etc. I suspect it is one of the first two so you are probably looking at 3mm or 6mm screened river gravel. Colour will depend on the river it is taken from. You may need to add sand to the mix depending on the source.