It is hard to explain what makes acrylic inks so unpleasant. Some people like them. If you want or need waterproof, then it is worthwhile to try the Ziller inks. They are not unpleasant at all - IMHO - you just don't get the finest hairlines - and on certain papers they are just fine.
I like Holbein Acryla Gouache when I need something waterproof - but it is not as dreamy as regular gouache.
I have never found an inexpensive gouache that works for me, but I know there are people who have no problems with it.
It is fine to ask for opinions, but you need to try things out yourself.
Many people agree that within a certain brand of gouache - even the expensive ones - there is a difference between certain pigments.
WN Indigo is dreamy. A lot of the greens require frequent stirring. They settle faster than other colors. Cerulean blue is another favorite.
Using just the primary colors is a good option.
There is a big difference between the blacks.
One of them is really slimy - but I do not recall which one. Lamp black, Jet black, Ivory black, Mars black, and Perylene Black
In the whites, one is better for mixing and the other is much better for highlights - but again, I can't remember which is which.
There is zinc white and permanent white.
My foggy memory thinks that zinc white was recommended for mixing.
I just googled the question and here is just one of many answers:
Permanent White is the whitest most opaque white but is not recommended for colour mixing. Zinc White produces the cleanest, most lightfast tints. Bleedproof White prevents underlayers from bleeding through, particularly those colours marked ‘BI’ on the colour chart. And finally, Process White is for photographic retouching, where it will reproduce its true value.
This leaves out "Titanium" white. That's among the whites available from Graham and others. What this is for, I dunno.
***you can google the question about blacks and find many responses.
Maybe others will add their 2-cents.
And, Daniel, if you have not heard about mixing up your gouache and then letting it sit for a few hours before you use it, that is important to know. For some reason it isn't quite as dreamy when you first mix it up. Use distilled water to mix the gouache. When you are through for the day, you just let the pans dry. Next time you want to write, you reconstitute the gouache. The tubes are pricy, but there is very little waste.
I'll be home tomorrow, Daniel, if you want to stop over and pick up that big box of Letter Arts Reviews that I keep trying to get Hunter to deliver to you. Or PM me your address and I'll drop it off.