For cures training you try to get your mage attack bonus as low as posible. You do this by wearing a full set of metal armor and a kite shield. (anything bronze-rune works) Then just go find a monster and curse it to your heart's content
The sigs you are talking about are made by talented artists and are generally custom made or premade. On the gallery board here, you can sometimes find people who give away their sigs.
All the black armor has the same stats as regular black armor. All the wizard armor has the same stats as regular wizard armor. All the leather armor has the same stats as regular leather armor. All the rune armor has the same stats as regular rune armor. All the addy armor has the same stats as regular addy armor. All the d-hide armor has the same stats as regular d-hide armor. It's mainly just for looks or status symbol.
Go kill a bunch of dragons. keep the bones, sell the hides, and buy more bones. It's less xp than ectofunctus per bone, but it's faster. (350% xp instead of 400%) Requires both burners to be lit
~5559900xp needed in your plan. at 30000xp per hour = 185.33hours. at 35000xp per hour = 158.85hours. at 40000xp per hour = 138.99hours. at 45000xp per hour = 123.55hours. I doubt you can get much higher than 45k xp per hours on f2p. But best of luck to you.