I'm sure you will get lots of opinions, because everyone will have their favorite!
I've been stamping and coloring images for quite a while with alcohol markers, i.e. Copics (I have a very few) and the Bic Markits and colored Sharpies.
I use a 110 lb cardstock that I get at Sams Club for all my cardmaking, including stamping and coloring images. I also use this cardstock for the bases for my cards, as I make card fronts and adhere them to the white plain base.
There are lots of more expensive cardstock brands out there, and you can pay a lot more than I pay for what I use. I am very happy with it, and haven't felt a need to buy the more expensive papers. For about $8, you get 250 sheets.
Here is a link to it:
GP - Image Plus, Card Stock Paper, 110 lb., 8-1/2? x 11?, 1 Pack - 250 Sheets - Sam's Club
I have a Canon printer with the outside paper feed that goes through the printer pretty flat, and I have no trouble using this cardstock in the printer. If you have a printer that takes the paper inside and wraps it around a roller, you might have a problem with any cardstock. I think it depends on the brand of printer.