I've been using PH martins for the majority of my paintings. The problems is I mostly like to paint Japanese imagery and the PH Martins are way too vibrant. I'll start with the outline and black shading, be perfectly happy until I lay that first color and it shines like a rainbow. That being said if you dont mind super vibrant color PH Martins are incredibly easy to work with and settle very evenly. However I recently started using FW Acrylics and I'm Much happier with the look. It's a bit more opaque, Doesnt blend as easy as watercolor and once it dries its no longer workable but the subtle colors are what I've been trying to achieve for years its a way more "traditional" look I guess. Plus they are lightfast where PH Martins are not.
As far as Brushes go I've used tons and settled on Sable being maybe favorite. Alot of guys will tell you it doesnt matter but I can tell the difference.
The Arches blocks are what I use about 90% of the time and I've been pretty happy with them. Cant tell much of a difference between that and the big loose sheets.