While I'm sure somebody has 3/4" engineered, it's not the norm for engineered hardwood. 1/2" and 5/8" are typically the top-of-the-line products in engineered. Something with a heavier top ply vs. say a peeled or rotary sliced (very thin) face. A good urethane wearlayer with aluminum oxide will also perform best. We handle a line of white oak called Barlinek. It's made in Poland, and they are the second largest hardwood flooring manufacturer in the world behind Kahr's. Very high-quality, well made product with multiple installation options (float, staple, or glue).
Another thing I'd add is that the NWFA (National Wood Flooring Association) has revised some of their installation standards in the past few years due to the trend for wider planks in hardwood. As a result, if you're using a product wider than 5" and you have joist spacing wider than 16" O.C., you need to make sure that you have a minimum subfloor thickness of 1 1/8". This is to prevent deflection in the subfloor. You also need to do a "glue-assist" even if you're installing the floor by stapling or nailing. This requires a serpentine bead of adhesive on the back of each plank. A lot of people aren't up to speed with that and miss that it may require raising the height of the subfloor, which could cause issues with wallbase, fixtures, cabinetry, etc.
Best wishes and good luck with your project!