if the forks and tubes are bent then your best bet is to probably get a used set off of fleabay.
easiest place that i've found for some of the replacement parts you need is
Honda XR50 parts CRF50 parts Z50 parts CT70 XR70 CRF70 parts performance KLX110 parts DRZ110 accessories XR100 CRF70 XR70 CRF100 NOS Honda pitbike pitbikes XR50 Z50 Honda minitrail CT70 Honda NOS parts Z50 CT70, Honda trail 50 70 , Honda Z50 CRF50 QA and
DrATV OPERATES HERE it's really all in preference.
suspension on these things always leave something to be desired. you can get stock reproduction units or get some snazzy ones that'll run you some good hard earned cash.
look through a bunch of the old threads in the z50 section and it'll answer a lot of your basic questions.
welcome to the addiction by the way.
edit.. looks like rc has you covered.