ideally uplighting sconces on both sides of the mirror approx 5.5' from the floor

I'm not sure that side sconces will be an option between having to use a smaller med cabinet (loss of needed storage space) and the extra electrical work. Since above is the best option, which provides better lighting for makeup application - up or down? The dated Hollywood lights are great for that.

Uplighting means a light source placed such that the light is directed upwards towards the ceiling.

If the bare bulbs/ lamps are above the mirror , the face of the person using the mirror will be down lighted.

Down-lights provide much better light for putting on makeup than up-lights. In the house I sold last July, we started with an 8-light hollywood fixture (fabulous lighting, but UGLY). Updated bath to put house on market and put in very bright 4-bulb up-lights, which underperformed so significantly that we had to replace them with 4-bulb down-lights. Still not as good as the hollywoods, but acceptable. In this house, the mirror has sidelights. Not sure why people generally say sidelights are to be preferred because these give terrible light--okay for hair but useless for makeup. When we remodel, those sidelights will be replaced with down-lights.

The side lights were not providing sufficient illumination.

The rationale behind preferring side lighting over down lighting is because

1. The position of the downlights cause shadowing when the recessed light is located directly above or behind the mirror user's head.
2. Side lights are usually more diffuse, in front of and closer to the the mirror user's face.
3. Downlights with narrow cones of light would be problematic

Downlighting will work if the downlighting provides a more diffuse output (and sufficient) and is in front of the user's face.

For example, a linear light right up against the wall with the mirror, spanning the length of the mirror and providing sufficient lighting.