Simple and easy to read.

[Trailball]

I am retired and older eyesight.  I have great trouble searching for a simple easy to read watch with large Arabic  Numerals. Don't need day of the week or date.  Want an Eta quartz movement in a divers case with a screw on back.  Would considered building it myself to get what I want.. 

[spectre6000]

Well... The simplest way would be to just look at brands within the Swatch Group (owns ETA). They've got brands up and down the price scale. Dive watches have been en vogue for some time, so that parameter shouldn't be too challenging.

Beyond that, you're digging through the ETA catalog and finding movements you think are worth looking for, then googling them. I think you'll find movement details sparse in quartz land, but you might get lucky. Again, dive watches are the hip thang, so that shouldn't be a huge limiting factor. 

In either case, "easy to read" is pretty subjective, so you're subject to your own judgement with that parameter.