I used a Zebra G nib. I found these on Amazon, and they were such a good price I had to give them a try, and I'm really enjoying them.
Honestly, if you're looking for a cheaper option, I use the Huion 680s and I've never had any qualms with it.
The one I have is wired (not wireless), but I don't mind. The stylus is wireless, and I actually upgraded to the rechargeable one, but TBH the batteries in the AA battery one last a LONG time.
For tablets, lots of people go Wacom, but I never had the money for them. And I've never felt I was missing out.
I use a clear acrylic triangle that has a grid on it, something like this one: https://www.amazon.com/dp/B004MGLQWY/ref=cm_sw_r_cp_awdb_ajVDzbRJKP5AZ
You can probably also find something like that at a arts/craft store or maybe at some office supplies store.
I second Tombow Dual Brush pens, but there is a learning curve. You have to hold the pens at an angle to avoid fraying. Also, certain papers can cause them to fray as well, so you want really smooth paper (such as Rhodia, found on amazon)
To get a good feel for thin upstrokes and thick downstrokes though, I always recommend the Tombow Fudenosuke brush pens. They're much smaller and easier to learn on in my opinion.
Then I moved on to Tombows and Artline Stix Brush Pens.