Here's another quick update. Not sure why I didn't post this at the time, but here's a small lace frontal piece I made using the Hugo Royer 40 denier Standard Stage Lace. Although this is the least delicate lace they offer, it still disappears amazingly well on the skin. I can't remember how this is attached, but I would either have used Ghost Bond XL or got2b glued Spiking Gel.
It is ventilated using custom-dyed Brazilian remy hair that I bought on eBay, and heat resistant synthetic hair for the grey.
The advantage of using synthetic hair for the grey is that you can dye the piece if necessary, and because synthetic hair doesn't accept any colour, the white hair stays white.