Jaeger Alpaca 4 ply

I've been lurking for a while, watching what everyone else is making and trying to decide which shawl to knit first. I have decided to use some Jaeger Alpaca 4 ply (deep purple) that's been in my stash for a while, and I've just had some KnitPicks Options needles through the post today. All I need now is the pattern ;) At the moment, I'm leaning towards the Large Rectangle in spider net (page 24) or the Melon pattern (page 146). Before I start, I'd be interested to know if anyone has an opinion on the suitability of this yarn (i.e. do you think it'll be too thick/thin?)