The ideal sweater pattern for you may be the Five-Hour Baby Sweater. It's top-down, it's done in worsted yarn, it's knit with size 10-1/2 needles, and the pattern is at http://www.fibergypsy.com/patterns/5hrpa... I just got through doing one with a bonnet for a girl and one with a hood for a boy. If you think the basic pattern is too "lacy" for a boy, you can make an adjustment to the decorative stitch forming the yoke that will close up the holes. I also am adding buttons to the fronts.
There is also a cute pattern at http://www.plymouthyarn.com/index.php?na... . This one uses size 9 needles, but it will also take a soft worsted-weight yarn. I use I Love This Yarn from Hobby Lobby or Caron Simply Soft or even Plymouth Encore even though Plymouth recommends Fantasy Naturale.
My daughter thinks that ponchos are better than sweaters. I knit this one from Lion Brand Homespun (http://www.lionbrand.com/patterns/70358A... ) for her two-year-old when he was first born, and he wore it for two winters. She said it was easier to get on him than a sweater and it covered his front. Here's a similar poncho in a different yarn: http://www.lionbrand.com/patterns/kjif-babyPoncho.html?noImages= .
P. S. The Five-Hour Baby Sweater has been a perennial favorite of people knitting for charity, and several variations have developed. This one, http://gailbable.tripod.com/id41.html , showing purl ridges instead of lacy holes, is similar to the one I usually do for boys. I usually put 3 to 5 buttons, and I prefer to do the whole body and finish the sleeves last, knitting in the round. Thousands have been done finishing the body last, so you can't go wrong either way; I just don't like to sew the sleeve seams.
I love gray sweaters, and if it is a cable knit one, that is even better, those are cuter... you have a lot of options.
You can wear it with kahkis. Beautiful kahkis will bring out the grey color and details of the sweater.
You can wear it with a skirt, perferably a pretty colored one, like dark red. Since it is fall, you can match this look with tights.
You can wear it with a pair of dark jeans, and wear a white collered long sleeve shirt under the sweater, with the collar out. The white will bring out the dark denim and the grey sweater. With this idea, add a colorful detail to the look, like a colorful scarf in your hair, or pretty dangly earings, or a vintage pin on your sweater.
You can wear it with light colored jeans (my fav) and to spice things up, wear a scark around the hip area of your jeans, where a belt would go.
Girl, you have MANY options, just be yourself and have fun with your beautiful sweater!