Viet nam is increasingly more competivtive over all other countries in textile manufacturing. We have plenty of brands with " made in Viet nam" due to low labor cost, skillful workers and most important the reliability.
I have been working in textile industry for 8 years with wide network of manufacturer, from very small private workshop, to very big company.
For your requiremnt, i think it will best fit with a workshop with about 10 workers. With that small size work shop, they will be flexible with chances in design and happy to produce small qty per design. I already have some contact in hands, therefore the list of supplier can be availbel quite fast (in 5 working days). Then, I would analize with them your design and evaluate their quoation for reasonable prices.
In case you are interested in my bid, please be in contact