Runes or champs?

So I've started to try and be serious about climbing the ladder a bit (want to hit gold at least) and went from bronze 3 to silver 4 in the last few weeks or month. Trying to decide if I should add a champ I might like to my ranked pool for variation so I don't burn out, or make my runes better?

My current ranked pool when I'm serious is Heim mid/top, Nunu jg, Janna support, and not playing ADC. I'm considering buying Kennen to play top/mid/maybe support, maokai top/jungle, or ziggs mid/can he top? The other option is to change the page I use for heimer in 90% of my games w/ him (he's probably about 60-70% of my ranked games when I'm serious about climbing)

Main Heimer rune page is Mpen reds/Flat HP yellows/Scaling AP blues/Flat AP quints. Thinking of switching in 9 scaling HP yellows for the flat ones. Not sure if this is a huge difference or not, and was hoping for some input from others about if it was worth getting a new champ that could play a couple roles, or throwing in scaling instead of flats? (Also feel free to throw out suggestions on a champ if you think I should buy one. I may spam Morg or Lulu to get comfortable w/ adding them top/mid/support if I buy runes and not champ)