you might want to take a welding course at a local junior college or trade school as anything in auto building will someplace require some welding

If you are going to build a car---first the type of car and end presentation---
Next the wheels and tires that you want to use--front and rear suspensions so the wheel/tire will fit under the car---frame mods to allow that---

NOW LISTEN CLOSELY---after you get your frame set up you will want to support it level either on the suspension OR at THREE points so there is no twisting force on it---now as you work on the body and work with door gaps,etc you will have the car look like it is when its on the suspension on the ground and your wheels/tires will fit