70mm is getting hard to locate which is a real shame. Having the option of shooting 50-60+ shots on a roll of film was awfully nice at times.
Kodak Portra is still fairly common (used a lot for "mass" portraits like school pics, etc) , and the B&W aerial film that is still available is a slightly more IR sensitive (to cut through haze) version of Plus X. I believe there are a few others, but the selection is drying up fast.
Most of the 70mm equipment will be found used, on Ebay for the most part, these days. It may take a few months for everything to "pop up", but I have seen several of all the items below there in the past year...
A Watson 70 bulk film loader will let you roll your own cassette from the long rolls. Nikkor made a 70mm tank/reel that you can still locate on Ebay from time to time. Often just the reel is available by itself meaning you have to improvise a tank of some sort. I would look for one of those and develop your own.