Re: Linear Rails Various MFGs.
Rails are hard to oversize, apart from the simple issue of how much space they take up.
Ball screws - bigger is not better - need to be appropriately sized.
Hiwin are probably the cheapest and most readily available of the recognised brand name linear rails, or ateast were in years gone by. There has been a big increase in availability of Chinese brands in recent years. Can't speak to quality / accuracy.
7xCNC.com - CNC info for the minilathe (7x10, 7x12, 7x14, 7x16)