Couple of thoughts. Studs are studs, 8' and 10' lumber is not. The difference is that a stud is typically 92-5/8" or 92-1/4" depending on what part of the country you are in. They are also "PET" or precision end trimmed, so they will all be exactly the same length. Dimension lumber just needs to be at least the length it is sold as, so a unit of 8' 2x4s could have everything from dead on at 96" to pieces that are 3/4" longer. Now you might find that the 8'ers you buy are also PET, but it is something to be aware of. Second, I would make a "story pole" that is the height of your theoretical wall, and us it to gauge exactly how far off your desired height you are, all over the floor slab. Chances are that the bottom of the floor joists create a very flat plane, but the concrete floor can be a wild card. large shallow dips and slabs that slope, slightly, from one end to the other are pretty common. Finally, I typically build these walls a 1/4" short and tilt them up. I then drive shims between the floor joist and top plate, at 32" on center, and use timber screws to secure the plate to the ceiling. I would secure a plate to the floor with TapCons, and stand my wall on top of that, using pairs of 10D nails to secure the bottom of the wall to the bottom plate.
EDIT: I'm guessing that you are furring the bottom of the joist to install sheetrock? It sounds like you are in a really restricted area, code wise. Don't forget that you will need an access hatch in the ceiling for every junction box, water valve, and hvac damper or other serviceable mechanical item (tub drains, sewer clean-outs, motorized dampers, zone valves, door bell transformer, etc) Pretty much why drop ceilings are SOP in a basement build-outs, since a rocked ceiling, with a couple dozen hatches often looks like crap.