I've got a couple of events coming up that I'd like to wear a dress to, but I have more trouble with dresses than with anything else, and am a terrible judge of what works and what doesn't.

Here are the challenges:
1. It seems like every dress I try is shorter than I'd like. I have slim legs, but I want to be age-appropriate.
2. I'm pretty much limited to a sheath style unless I do major alterations. Dresses are usually too small in the waist and too big in the hips on me if I buy them to fit through the shoulders and bust.
3. I'm looking for something with sleeves, since my aging arms are not my best feature.

The two major events are a wedding and my granddaughter's First Communion. Here's what I have so far. The tags are still on both of these, and I'm welcome to other suggestions and ideas. It needs to be something new, because I've lost weight since last year and don't have any dresses that fit.

For the wedding I was thinking about this Laundry by Shelli Segal dress. I like the color, and the scoop neck in the back, and it's marginally long enough, but I'm not totally sure how flattering it is. And is it appropriate for a 5 pm wedding?

For the First Communion, I thought about this Alice and Olivia dress, worn with my new BCBG jacket (one of Angie's picks). This dress is a little shorter than I'd like, but otherwise I really like it. It's a substantial knit that's quite flattering, and would pack well for travel. It would be a cute casual dress for summer when it's hot enough that I lose all shame about bare arms. The question is, is the length a deal breaker? Does it look OK with the jacket?
I'm pretty sure I'm keeping the jacket unless given reason not to, although the color is not one I usually wear.
(Bonus shot of blush jacket with jeans- excuse the goofy expression!)

So, does anything here work, or should I go back to the drawing board? If these are a no go, can you recommend any specific dresses to me?
Thanks so much in advance!