Oct 8 (Reuters) - U.S. stock index futures rose in choppy trading on Friday, with tech-heavy Nasdaq futures leading the way after data showed September job gains were far short of analysts’ estimates. At 8:40 a.m. ET, Dow e-minis were up 7 points, or 0.02%, S&P 500 e-minis were up 10.25 points, or 0.23%, and Nasdaq 100 e-minis were up 89 points, or 0.6%. (Reporting by Sruthi Shankar in Bengaluru; Editing by Maju Samuel)