The "fittedness" of the design/pattern suggests to me that swatching may be necessary to see if you'll be knitting to the gauge in the pattern so that your FO will indeed fit you. Then, too, you could use smaller or larger needles to get a slightly smaller or larger size...but you won't know if you should do that unless you first know whether your current yarn & needle size are giving you the gauge of the pattern.
Your yarn gives:
Gauge: 4 1/2sts. = 1" on #8 needles
Pattern calls for:
Classic Elite Classic Silk (50% cotton, 30% silk, 20% nylon; 135 yd (124 m)/ 50 g which gives a
Gauge of 5 sts/inch on #6 needles
hmmmmm........there's a bit of a difference there.... :??
I think I'd swatch in order to not be disappointed when I was finished.
P.S. It just occurred to me that a 60% angora 20% wool 10% nylon mix could be quite warm...which is probably why most of the [color=blue][size=6]designs[/size][/color] shown in the yarn are winter-type items.