OK, frame looks not a million miles away, I'd make sure that the top rail has a thick wall otherwise it'll resonate with high frequency vibrations from the spindle. Bed looks like it could do with a bit more bracing.

Electrics, don't buy a "kit" of parts from one seller as they're always compromised in at least one area. If you're going to use Nema 34 motors (Z axis won't need it unless you're planning a monster?!!) then they need at least 100V to make them perform, best to use a 230V driver to get the best performance. If you're determined to use lower power drivers then use ones that can take 80V and build your own power supply to get the best performance.

Ballscrews, for wood you'll need speed so I'd use 1610 ballscrews on your X & Y axis and 1605 on your Z only. But at this length you'll need rotating ballnuts on a fixed (clamped both ends) 1610 ballscrew. Otherwise you'll need to go up to 20mm ballscrews and possibly 25mm, couldn't say which without doing the calcs for speed etc.

Couplings, use belts, this enables you to swap pulleys to increase/decrease the speed/resolution and more importantly it stops resonance being transmitted to the stepper motors.

Spindle, you can't got wrong with a 2.2kW water cooled spindle with inverter, the type you get from eBay....I've got one and they're great!

Other electronics will be things like relays and other electronic components (fuses, din terminals etc. etc.) to build your control panel, limit switches what controller are you thinking of?