OK thanks to everyone for the answers BTW D.C there is no need for apologies, it is OK :).
I am planning to use the CNC for milling some thin aluminum, then wood, plastic, that kind of materials.
I am forced to make the support for the linear rails because those parts are really heavy and the shipping to my country is $$$.
I have the roods from pro-chrome but I need to make the support rails. Now this is really a problem so that's why I am asking for help.
I was thinking of using two L shaped profiles and one aluminum bar in the middle like sandwich and tight that up with nuts and bolts on every 5cm or so. Like this

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I know it is not perfect solution but what do you think about it? Can you give me another idea of making the support rails?

THANK YOU VERY MUCH for the understanding.