Dress for a summer wedding (guest)

[Ohthepressure]

My DB is getting married in the summer, church service followed by reception.

I am travelling over from Australia for the wedding, high street clothes shops here are pretty dire, and I am very wary of turning up in the UK with 3 days to find an outfit. I just have work clothes and jeans/casual clothes, not much beyond that.

So I've been looking online at those cheapy stores which lurk at the bottom / side of MN threads, amongst others. I'm not sure how sensible this is, but I have 7 months to go and can wait for delivery from China or wherever.

I am 5'6", a somewhat wobbly size 16, and am aged 45 (and a bit) with silver/grey hair.

What do you think of these dresses? I'm concerned the silver/grey ones might (a) blend with my hair too much and (b) look a little mother of the bridey. I'd rather have arms slightly covered. They are however bloody cheap, so I'm quite happy to wear once and never again look at the photos!

Any ideas?.