It is sad to see MM paints discontinued, sort of reminds me of how I felt when GM dropped Pontiac and Odsmobile from their lines. At one time Testors was the high standard of the hobby and has let it go, or better said, the new owners have let it go away. So yes it's time to regroup.
I haven't yet bought a tin of Humbrol, but I understand that it's still very much available; either Sprue Brothers or Scale Hobbyist stock it, or you can order from Hannants in the UK. In acrylics, Tamiya has led the field for a long time, and is pretty commonly available. It's a solvent based acrylic, so you thin with their own X-20 or you can use othe lacquer based thinners or isopropyl alchohol. It sprays very well, and brushes OK with Tamiya Retarder. I like Tamiya overall, but am frustrated with their lack of specific colors (RLM, US Federal Standard, etc.) finding that it can take a lot of mixing to get a good match. Since I have to order my paints online in any case, I'm going to branch out and try TruColor, AK's Interactive and Real Color lines, and GSI brands.
I don't mind the prep and prime phases, I do that no matter what final paint coating I'm using - it helps point out flaws prior to finish work and makes for a better result overall.
There are other solvent based acrylics out there and then there are "true" acrylics that are water based. Hopefully other forum members will come in with their experiences.