Don't have to bother about the 'look' of the cert, both of you will properly see it once and stash away for donkey years.
Realistically speaking, her friends will be looking at the ring with naked eyes, which obviously cut and size will be the only thing they notice. Just maximize the size within your budget with G color and VS 2 for the best visual experience.
And also not to worry about the color....to be honest, the only time they can notice a tiny difference in the color is if someone actually put a D/E color ring next to your ring on a side view under a white fluorescent lighting and stare close to it for more than 3 seconds...which i doubt anyone will, because it's plain rude.
Anyway are you sure she will prefer the Solasfera cutting? Initially i thought it was nice too, until i showed it to few of my female friends and even my partner...all of them preferred the super ideal in person as Solasfera in small carat size kinda look 'messy' due to the tinier bling...IMO it'll only look great if you're looking at 1.2 above.
PS: If your partner prefers super ideal, you can further up the size due to the pricing

...imagine a 0.7 super ideal vs 0.5x Solasfera...the former will probably be more awesome