New sweater project... can't wait!

I have ordered yarn for a sweater. Here's the super cute sweater I want to make. And here's the yarn I ordered. Colorway: 9420 Como Blue. I'm thinking the long sleeves, but depending on how long it takes me... maybe it'll be warm enough out for the short sleeves.

Now, you all will have to hold me to the swatching. I promise I will swatch 1st. I will make sure my gauge is dead on before proceeding to cast on in a whirl of hormones. It's 128 stitches to CO, so I will try not to take this lightly.

One question though... sweater is knit in the round (Hallelujah!), but would swatching a stockinette pattern mess up the guage? IE: all K vs. K/P alternate rows? I THINK my P rows are the same size as my K, but I don't know for sure. I had never even THOUGHT of that being a problem, until I saw it on a Q&A knitting site. See, these are the things that make me throw up my hands and CO blindly and hope for the best... so. much. trouble. :)

Here's hoping yarn arrives by tomorrow. We're going away for the weekend to a wedding in IA, and I want to swatch! And/or fondle the new pretty yarn. Turns out that the B&B I booked for this weekend has a LYS within walking distance. Coincidence? I think not. :)