I am looking for a Flash with softbox cover for my D50 (Upgrade soon) that will last me for a long time and that I can use with newer Nikons. I would like to use it to shoot models against the sun, sunset and indoor. Also I like to experiment with it. Spending up to 1.5k. Like to spend 800. What should I be looking at?

the very lowest you could get away with would be something like a lumedyne. Better would be a hensel porty or Elinchrom ranger. I personally have a ranger and absolutely love it. Unbelievably powerful, huge dimming range (all while maintaining color temp), tons of accessories. In a small shoulder bag I can fit the pack, 1 standard 1300 watt head, 1 1200 watt ringflash, 1 compact stand, and 1 mini octabank (22"). Plenty of power to overpower mid-day sun, even through a large octo.