As a few people have said, what price do you put on your life, this is the issue with the DIY'er they tend to 'cheap out' and are completely surprised when it all goes **** up.
For sure I want to be safe that's why I'm asking.
And that's why I'm considering solid wood because it seemed to be stronger than metal to me. It's more effort not less, to build your own wood ramps which as you say will weigh a lot more too.