If you don't come up with a source you can always go to your local glazier and place an order for a piece of tempered glass to your specs.

I need a sheet for my STTNG is that all I ask for is tempered glass? What about the edges are they not smoothed out to avoid getting cut easily?

Glazier can sand the edges. If you have at least an intact glass, just take it to them.

Just go to your local glass supply place and ask for:

Standard: 21" x 43" x 3/16" tempered glass (no logo)
Widebody: 23.75: x 43" x 3/16" tempered glass (no logo)

Some other manufacturer's wide body games have different dimensions, so measure before ordering.

The edges will already come semi-finished. You can get them polished; but it's usually another $10 for that, which isn't needed.

The prices vary from place to place so check around. It may even be cheaper to have Pinball Life ship you two as my local place tends to be a tad expensive ($40 for standard + tax).