Ok i hope this helps, i have done a little painting in my time and the first thing i can recommend is DO NOT TOUCH THE SUPERCHEAP PAINTS!!!!!!, they are absolute rubbish, only use them if you feel like repainting in 12 months time cos it has all flaked and chipped off.
there are plenty of auto paint suppliers around, olarenshaws in sunshine, body shop in thomastown and many more, get yourselff 500ml of paint mixed up and get some clear to go over the top, if you are going to all the trouble of sandblasting and welding you might as well do it properly and save yourself some time and money down the track.
i heard you live in sunbury, i am near tullamarine, if you need a hand or someone to spray it for you give me a yell and i can help you out.