Hey JAZCNC Thank you so much for the help, Yes the rails are the supported type thanks for the names to search on the Forum, One of the problems I have had is not really knowing what to search for really so head through A little aimlessly.

I would like to make it out of steel really because I would like to get the practice using the tig, Although I was looking around and steel seemed to be a similar cost to the profile but didn't really think of the fixings costings being as high as the profile.

I bought some steel once from Mild Steel Online | No Minimum Order | Free Delivery On Orders £70+ and they currently have a 10% off mild steel but it doesn't say if it is Cold rolled or not as I have read on here that it is better to go for. For the steel cnc design I did favour the high sided cage design with the rails high and then the gantry sitting right on the rails as it seemed more sturdy but I don't know if this is best to opt for or go for the standard gantry design.
I was also unsure how to really get the frame square if I have to buy a digital level instead of a spirit level ?.

I guess if steel was ever really needed a plasma add-on is always possible but when I have watched youtube it doesn't ever seem to be a Sharpe cut.