Once again. The length of a table is of less concern than finding control electronics that will survive in the harsh environment with the HF plasma unit you use. A piece can be indexed to cut but it's more about the CAM software than the table. If you do an online cut (no offset) you can stop it and then join up a second continuing cut. It would need to be laid out that way in the cut program.
You are looking at $10,000 machines and trying to make them equal to machines that cost well into six figures by just stretching them a little. If you were cutting thin material (1/4" or less) with a smaller contact start plasma (like the Hyperthem 1000 - 1650 or TD81 - TD 151) then it just boils down to the physics of moving the added mass of a wider gantry. Like a bridge, the farther the span, the more rigid and the more mass you need to prevent bowing. The table length can be 50' if you want it. It's about the noise and HF start of that huge plasma and your desire to be able to cut anything you throw at it.
You need to talk with a few users of PlasmaCAM that actually do the indexing and see how painless it really is.
It also requires accurate table stops and guides and a lot of operator patience.
If you read their marketing material PlasmaCam has everything you will ever need/want.
Just be aware that that is a completely closed system and all support and repair parts will have to come from them.
Tom Caudle
www.CandCNC.com