With my method to create isometric blocks, I did a test using Minecraft standard texture, easily available on the net, and I created a whole set of blocks.
Each block is a separate 200px png file with transparency, but the source is a vector so any size is possible.
13 October 2016: added some missing blocks, redesigned the vertical sign
18 October 2016: Added shulker boxes, birch door, iron trapdoor, lever, observer block. Revised wooden trapdoor.
17 November 2016: Added jungle door, revised regular and trapped chests
27 February 2018: Added glazed terracotta, stained glass panels, red sandstone, banners, changed disposition for a better showcase
09 March 2018: Added Concrete, Concrete powder, Prismarine, Prismarine brick and Prismarine Dark stairs & slabs, Mobs heads, Kelp and Chorus plants, damaged Anvils, more wooden pressure plates
04 May 2018: Added Coral blocks, alive and dead, Coral plants, all trapdoors, all push-buttons, all peeled trunks