For the film for 135 film, I use the clicker system like : http://www.matchboxpinhole.com/clicker.html
Very convenient, even if people think you are stupid when you listen in a strange box you use like a camera.
1 mm for the diameter of you hole is really to big. I am not a big fan of formula (you can easaly find 10 different formula with different results, see here*). But clearly, 1 mm for a 28 mm focal will oblige you to very short exposures. You should try with a 0.2 or 0.3 mm hole.
ISO 200 can be OK. I use FP4+ and devellop at ISO 50. But 200 is still manageable.
Like bvy, I recommand the Populist, very fun and very good to start with.
*In French, but you will understand formulas and curves