That should be a perfect choice and in fact is one that recommended in the several existing threads here that deal with immersion cooling. It has 2 primary advantages over mineral oil:
 1) It does not attack plastics or epoxies - only warning is to NOT use any kind of silicone glue or sealant as it WILL attack them and turn them into a crumbly mass of rubber.
 2) It is a fairly thin fluid meaning it pumps and flows very well.

Don't know what temperatures you used to calculate the dry cooler capacity being 100kw but it may be able to handle more power. Of course depends on what your highest outside air temp can be but on the miner side, something most folks forget to account for is that miners like a VERY warm chip temperature. As in around 70-degC or more. That translates into you being able to run with rather high oil temp, you probably find that a fluid temp of 50C will work perfect.