The ceramic you will find in that range of values are multiple parts soldered onto a lead frame. Same as doing it yourself but somehow ten times more expensive...
Large value ceramics tend to be unusually expensive and poorly stocked, too, so you might consider using even more, like a hundred pieces. Which would be a fair amount of board area, so it might be double sided, or spread onto two or more PCBs connected with headers, or something.
Also, mind the C(V) curve, make sure you have enough of them to get the energy you require, or whatever.
If you need energy in a small space, go for higher voltages, period. Few components are sized proportional to CV^2 (i.e., energy), tending more towards CV (charge) for whatever reason. The difference between, say, 50V and 500V is so dramatic, it is well worth adding two power converter stages (if they're small and efficient, which is quite possible with the availability of power GaN nowadays) just to take advantage of that.
Or, like I said, rearrange the load so it can use the higher voltage directly. Say this were an LED strobe, you wouldn't run a single 100W "light engine" (30V 3A or whatever), you'd use the same number of dice in one long series string at 300V (probably having to use a lot of smaller LEDs since you can't find an all-series module?).
Tim