What kind of yukata is acceptable?

I am planning to wear a yukata to the Japanese Festival at St. Louis's botanical gardens, a lot of people wear traditional Japanese dress there. But I have hardly any money to spend on one, is it okay if I wear one of the kimono-yukata hybrids that are Chinese-made and available on eBay? They're made of a silky fabric and the obi and yukata are the same pattern, but the obi is pre-tied.

And, how should I do my hair, and what kind of shoes can be worn with a Chinese-made yukata? I have a pair of geta but they are huge and I don't think I'd look very smart in them.... ;) Would I have to wear tabi with them?

Japanese yukatas are made of cotton and are not silky at all. To me the silky "kimonos" that they sell at touristy places look like a bit like bathrobes, but if no-one where you will be knows the difference, and the obi looks like a proper yukata obi, why not?

Tabi are not worn with yukata as they are summer attire. If by geta you mean the wooden sandals then those are also not worn with yukata. You quite often see Japanese girls wearing flipflops or ordinary sandals with their yukata.

Although teenagers nowadays wear yukata with western sandals, properly, yukata should be worn with geta. However, geta for males and geta for females are quite different. Men's geta are square, a bit bigger than a typical man's foot and usually has black straps, while women's geta are more oval, slim, more fit to a woman's foot and has colorful straps.

The festival is to promote friendship and diversity so I'm sure whatever you wear is fine.

If you want authenticity, yukata is made from cotton. I don't know if Japanese goods are easily available in St. Louis and since you are on a budget, I wouldn't worry too much. Just make sure you wear it left over right

Wear your hair in an up-do or a high ponytail, softening the look with curls if you want. It looks best if your hair does not cover the eri (collar).

Find a suitable pair of flip-flops. These are popular, easy to find and should be affordable. These are much better than heels or athletic shoes.

If a bon dance (folk dance circle) is part of the activity--join in and have fun!! Not to worry how you look but just enjoy yourself.