We got ours from Denny’s. They also do compostable straws, plates and glasses. In fact everything you need for entertaining.
Since we bought, a lot more companies have started to offer compostable party ware and new products are appearing all the time. It would be worth looking around.
There are those who say you cannot compost PLA plastic in home composters. We did. The knives did biodegrade. It took some time but it happened. However we do have a Green Joanna, the queen of compost bins.
We rented the extra stuff we needed for the party from a catering company . We probably could have hired cutlery too but we were curious to try the cornstarch stuff.