well i still dont know what are stage one mods... wellas far as turbo is concerned, yeah you can turbo any engine which takes in aair as intake, but my question is do you realy need it, you will ruin your perfectly fine reliable car.. as far as rpm is concerned, in normal day to day driving i willl suggest you 3~3.5k. to give you better economy, otherwise i think alto redlines at around 6, but not aure about it.
cheers