What a gorgeous sweater.It is knit on aran weight yarn which takes up more room on the needle than lighter weight. I usually use a 24 or 32 inch needle for most of my top down knitting up to size 40. However I always have another needle with a longer cord so I can try the project on as I go. I knit off half the sweater before taking off sleeves and again if shaping waist. This is where interchangables come in handy. If possible have more than one length cord. Also you will have a lot less stitches when you put your sleeves on Hold, so again two different cord lengths might be best.