The only way for me to try a linear psu is by buying one. That is no problemen but if it isn't sure that it will solve the issue then its like throwing money in the garbage bin
So looking around to see what kind of linear psu i can find. I came across this one i think this one is perfect for the job. Did not order yet, still waiting on other tips :D
http://nl.mouser.com/ProductDetail/Sola-Hevi-Duty/SLS-12-017T/?qs=sGAEpiMZZMtl%252b%2ft8G5TWgN7SYPj5Kq48atvObpxO30E%3d