lelong.com. bought there before

i also bought two from there

You should be able to buy also from Lazada and 11Street. Currently, I'm having no issue charging my PS Vita (model 2000) using my smartphone fast charger and power bank. This should also be the same for the 1000 model, only that you need to have the cable from USB - PSV to replace the regular USB - Micro USB cable. PSV cables aren't that expensive (should be below RM30 per piece), and should work perfectly fine with recent stock smartphone chargers.

Yeah. I've charged my vita 1000 and 2000 via a power bank.

The head is not micro USB but some proprietary head.
But the other end is your regular USB A head.
Plug that to any power bank and it'll work.
At least it worked with my xiaomi and eneloop power bank.

As mentioned by LegendLee, the proprietary connection is to the PS Vita itself, but the other end is still regular USB. You should try buying only the PS Vita cable first, and try to charge your PS Vita using your smartphone charger + PS Vita cable. Should work just fine with no issue, unless the charger's output is very low. If it works just fine (like the rest of us), it can save you the money from buying an additional charger.

To sum up : only the cable is unique for PS Vita 1000, while the charger itself can be used with other devices.