If Konan drip herself with water than she could win when fighting Deidara. If she plan ahead. But I think exploding bombs are useless against her. As seen when Jiraiya use his Fireball Jutsu to burn her during the "Jiraya and Pain" battle. So I think Konan would win.
I vote Konan. Something about her tells me she knows a lot more than the manga gives her credit for. she WAS trained by Jiraiya. I think she would outsmart deidara any day.