I think you mean Ester oil, short for Polyolester, often abbreviated POE.

PAG is a much better lubricant, but it will not tolerate chlorine. Water either, but you can now buy double-end-capped PAG, known as DEC-PAG, which is much more water-tolerant. The stuff at our local parts store says "Super Moisture Tolerant Formula" or some such, and it is DEC oil. For PAG, you use 46cSt viscosity.

As for the chlorine, it appears that you will be using your old flexible hoses. You won't get all of the refrigerant out of them, so there will be chlorine. If this is the case, I would go with POE oil, in 100cSt viscosity (I would use 100. What you use is up to you). Note that POE oil is also not water tolerant.

I would recommend fluorescent dye in the oil. You can buy it that way off the shelf.