I'm going to make Sesame (http://www.magknits.com/Aug05/sesame.htm) by MagKnits.

My problem is that I'm pear shaped and the sweater is sized so that the bottom is 4 sts smaller than the bust. I'm 3 inches larger where the bottom of the sweater would sit than i am at my bust.

Should i cast on more stitches and then decrease more often than the pattern recommends -OR- should i just cast on and knit the first 5 or 6 inches or so with a larger needle? I'm leaning toward using a larger needle and then switching.

What do you all think?

I would probably go the larger needle route personally and see how it goes. If that fails try a few more stitches and some additional decreases.

I think adding stitches would be a good idea anyway, to make it stretchier. Or skip the ribbing all together and make a rolled edge or a hem.