For 3D and isometric view, there
are Armok Vision and stonesense, but they're are more used to get cool screenshots and visualize battles than to actually play as it is. Closest to original game but still viewing more than layer at time, Text Will Be Text (TWBT) enables one to to see z-levels beneath open space (as well as having different tiles for same symbols in text and game view). All three require dfhack, of course.
However, note that for a typical multi-level fortress the floors are on top of each other, so you'll still be seeing just 1 floor at time. Even with transparent glass floors in Armok Vision, other things will be just in the way
While there's probably exceptions, people generally do the heavy lifting inside the normal DF screen.
Now, what to get - I'd say go ahead and take 43.03 pack - the 43.05 version main gameplay difference is combat wear, which will not concern much your first few practice fortresses. You can always copy-paste your save over if you want to upgrade later.
DFHack adds lot of quality of life options, and as a newbie you could put off learning about dozens of skills by using automatic labor assignment via autolabor command and try making your first drunk and fed outpost for a start; you won't be able to learn the entire game in an afternoon. I recommend following a guide.
(The vanilla labor UI difficulties compound cubically with time, so it's absolutely fine to learn with - what they're talking about is late game. )