Summer Gaius: Which Bow/Build

Back when the Ylissean Summer banner got a re-run, I finally got Summer Gaius after getting cucked hard on L!Ephraim's banner. He's +Attack, but -Speed so I had difficulty finding a good way to make up for the lack of Speed since I didn't have any fodder he could use. While trying to pull for B!Tharja on this Legendary banner (to no success so far), I got an extra Karla. I figured Speed Wave would be a good skill to give to Gaius to help patch up his Speed since I don't really need Wrath. If I did fodder her to him, what Bow could he make the best use out of? I was thinking Brave Bow, but he'd be at 29 Speed before Speed buffs. Any suggestions for what Bow he could make the best use out of? Passives too?