Shift+Click yourself the block you want to place and the block you want to replace. You know have 111 of both which means, infinite blocksI like your thinking, but it doesn't do well in creative mode, still requiring the same amount of blocks as normal and still giving you blocks. Do a stack or two of it, sure, but after that, get a Creative Builders Wand from Extra Utilities and use it on some grass. Its free on grass and can build upwards a block very easily.