Yes, that's what I meant.
You won't find a set with a Tsangan option on Taobao. Group Buy keycaps and other high quality sets are more expensive then $40 a set.
So you have 3 options:
1. Buy a cheap set from Taobao and replace everything except the bottom row. If you can find some TaiHao white on black doubleshots, they're very decent keycaps for the price and the profile should match well enough to be usable.
2. Buy a more expensive higher quality set that includes all the keycaps you need except the spacebar and use them with the stock spacebar.
3. Buy a more expensive set and also order a 6.5x matching profile spacebar from PimpMyKeyboard / Signature Plastics, although it doesn't look like that order will reach tipping point, so they're probably not going to make them. There just aren't enough people with odd layout boards ordering them.
Then, in future, buy a keyboard with a standard layout so you have more options when replacing keycaps