Hollywood lights is extremely helpful. The entire staff there is very knowledgeable about their makeup supply, and will even test out the colours on you to make sure you know exactly what youre getting and that your colours will blend in the way you want them to. This has happened everytime I've gone. We went to get makeup for my Jet cosplay to look tanner, and she tested probably 5 shades on me, she also found a proper shade for contouring and we ordered them no problem. Seriously, I cannot reccommend Hollywood Lights enough, we were just there a few days ago to pick up an order. Also, if they dont have the exact shade you want, they will order it for you and call you to let you know when its there. They even held ours for 4 months because we ordered a few colours in December and couldnt pick them up until just now.
They carry Ben Nye, Kryolan , and some lesser known brands. Kryolan's Aquacolor is good for blending, but Ive also used Kyrolan's Supracolor, which is an oil based makeup. It blends a lot better, but is rough on brushes and on your skin. But it lasts a long time and I use it for a lot of shading. For example, I use a white Aquacolor base, but once it dries I go in and detail with the Supracolor. I dont think Supracolor as a base works, but Aquacolor with Supracolor on top certainly does.
Hollywood Lights also carries many different kinds of sealant, and various sizes, and you can order a larger size if you need it. They basically sell anything you could need in terms of makeup, even super random metallic shades to a book of proper emotional eyebrow stencils haha
Sorry for the super long post but I hope it helps!