seeking leads/ideas/suggestion for companion cube cosplay

I’ve connected with a woman online who is the perfect match. We’re planning to attend a geeky fetish event together. She’s dressing up as Chell, and I’ll be her Companion Cube. ^_^ This is my appeal to all you creative folks on this forum lol.

I’m looking for suggestions on what items can serve as the foundation for this costume. I expect them to be solid grey, with me adding the decorations myself. I need to finish this project by November 1st—sooner would be better so I have time to test and adjust it lol.

The main priority is the dress itself. The boots will likely just become fuzzy rave-style ones due to time limits. I want at least a dark grey dress, keeping the color scheme consistent even if the style varies slightly.

I’m also seeking ideas for creating those round objects with hearts on them. Basically, any thoughts on finishing off parts of the outfit would be great. The aim is to look very much like this when it’s all done. Image

So far, the best base option I’ve found is this one. Image

I’m considering crafting the heart pendants from these items. I could paint them to make them glow effectively. Image

I’ve already ordered a fantastic pink anime wig, and I’ll pick up a silver one as well to decide which looks better lol. The budget is somewhat tight, but I’m prepared to spend a bit more if it means achieving something slightly superior or finishing the job faster.

Any thoughts on creating long fall boots or Portal guns would also be helpful; I can pass those along to her.