Of course we're gonna help you Kickn! You can buy motion parts from
www.ondrives.com in the UK, I have found their trapezoidal leadscrews to be great, and have made my own nuts from delrin which I bought on ebay. The extrusions you are thinking of using will be plenty strong, especially in something like 80x40 size. What are you wanting to use for a spindle, router or mini-mill head? Both will cut non-ferrous metals easily.