frame/seam WELDING HELP

[crazedfiber]

well i am part way thru my long journey on my drift project. i have the car stripped down as much as possible. sound deadener is gone along with all interior. i have my SR sitting out of its home and ready to get a new headgasket. put to the point...i am ready to stiffen up my chassis, i was wondering if any of you have done this to your cars? apexi's rx7 they said they drilled a whole inbetween every stock spot weld and then welded the two pieces together and grinded it back down flush. other ppl i have seen spot weld certain areas(im not sure where they spot weld) then there are some the sticth weld the seams up? can anybody tell me where all i need to weld and why? i also heard about foam in your door rocker panerls to stiffen the chassis. PLEASE help!!! thanks!