As someone who will shill the Fostex biodynamic headphones until the day I die, I can’t recoment them if you want isolation. They are semi-open since there is a small opening on the back around the entire cup. Also they will require some pad swapping to be as comfortable as you want, but it is possible. Check out this thread if you are really interested. Also they are not really portable at all if that matters.
If you are willing to pay more (about $600) you could get the TH-610 from Amazon and return them if you don’t like them. The EMU teak, TR-X00s, and TH-610 all use the same driver, but due to the cups and the dampening they all sound a bit different. The TR-X00 ebony and the EMU teak sound similar with a refined warm V shaped signature. The Purple Hearts are the most fun with big bass and the most treble (as seen in the graphs that have been posted) but are still no where as sharp as the DT770 and also rather warm imo. The TH-610 are a bit more neutral but still have great bass and are still V shaped like the rest of the family. If you are willing to put in a bit ofd work with pad swaps and some very light modding (attenuation rings) these are all great options, but I will again mention the lack of isolation and portability.