Hot press paper is best suited for stamping because it has a smooth finish (think of an iron as a hot press, smoothing wrinkles). Quality and results will vary depending on the brand of paper as well as the cotton content.
I use Fabriano Studio hot press paper for my cardmaking, in the 140# weight. I buy the biggest pad of 11x14 paper which is 75 sheets - I can make 300 card fronts from that amount.
(lots of choices here - be sure to check hot/cold press, size, and weight!)
https://www.dickblick.com/products/f...tercolor-pads/
Inks: for watercoloring I use Versafine Clair, Stazon or a hybrid ink - anything that doesn't react with water will be fine.