I dont want to my new kites for snowkiting.I have some Naish /Boxers that I want to use and would set up with a reverse launch line.Any suggestions or tips ?

Those boxers should have tabs on the lee edge mid struts for reverse 5th, If not the kites are not worth much, force some thick line Q-line works, through the webbing on the lee mid struts, part fibers apart dont cut, loop, knot, for attachment for reverse 5th with V to the struts.
This setup is one of the Best setups for relauch, works in very light wind.