Hi. I was the one that said Moda Bella and Kona solids play well together. I've used them together in an 8 step black to gray piece and a 12 step red to yellow piece, both all solids. Moda claims to have a sheen to the finish, but if I didn't know which fabrics in those two quilts were Moda, I wouldn't be able to tell the difference.
Hancocks of Paducah is the only place I know of that sells all of both lines and their prices are the best to boot. They do not send swatches, although you could try asking them and telling them why, offering to pay for them of course. I expect they would simply advise you to order the color card for each line. They sell the Kona color card for 29.98 and the Moda Bella card for 19.98. The places I know that do send swatches, free or otherwise, do not carry these two lines at all.
Hope that helps. You could get a lot of "wrong" blues for the $50 you'd spend on the two color cards so that's something to consider. Are there any quilt shops near you that might have the cards you could look at or borrow?