Dear Sukhum,
For item 8 and 13, they are common but requisite parts that are needed. Please inform the supplier to just send us the closest equivalent (brand and exact P/Ns are not important at all for such items).
Item 19, no necessary to buy. But it's not possible hardware shop no have paint trays (!)
Anyway, I had seen it with my own eyes there were item 8, 13 and 19 (many) when i went to Hardware House last week, and had thus written the P/Ns from actual goods i see.
My information is that, generally, staff at Hardware House are not very diligent so we need push them to get the goods we need or at least help us find the closest equivalent.