ok thanks everyone heres abit of an update to what ive done so far.
Ive got a windows pc with a Radeon graphics card, cant remember the number but will get it if its important.
I connected cab to it and same wavey lines, so setup a switch to have cab on one monitor and vga monitor on other so I can switch between the two.
I installed soft 15khz and it gave me all the options of 15, 25 and 31khz modes so told it to install 25 and then I switched over to cab and I finally got a visable screen
BUT and its a big but, the screen was sort of doubled and pasted on top of itself so I could see all the icons in windows but it was doubled. so I then tried the other modes and had exact same problem.
Then I had a light bulb moment and thought perhaps its because I have the resolution set at 1024 x 768 so the only other resolution I have is 800 x 600 but when I tried that the wavey lines came back again.
So im slowly getting somewhere but still not there yet.
I agree with everyone here, I will get the screen perfect first then worry about the rest but I sincerely thank you for you help so far, I have tried another forum who arent as friendly
Will take some photos while waiting for another suggestion.
Also ive had a look at the monitor on the cab to see what monitor version is like someone asked but theres no stickers apart from saying "warning this weighs 117kg" and other than the Sega, Virtua Striker 2 or Noami labels theres not much on the cabinet sorry