I am glad to hear that someone using this site wants to accentuate grain for artistic purposes. I recommend Tri-X rated 800 or 1200 and developed in Dektol diluted as for paper development. You will need to experiment with times. Also a temperature range of 75-80 degrees F will help enlarge grain to some extent. Back in the '60s grain was trendy, but now that most people are accustomed to the T grain emulsions, they work hard to avoid any appearance of grain. If film did not have any grain you would not have a picture at all. I say you should embrace the technology you prefer and make the best artistic use of whichever type film you prefer. Amen!