I suggest you get a 22.5" Weber Kettle for grilling things and also for roasting chicken/turkeys. And the WSM for smoking/bbq.
But I've never used an Akorn, so I don't know. With the WSM you'd have two levels of cooking grates.
Char-Griller makes Akorn; I don't know the quality of them. But I know Char-Griller has some issues with quality control with their offset smokers. So just personally, I don't think I'd buy that brand, but never researched it. I believe there are lots here that love their Akorn though.
I do know the OTG and WSM are both quality items that can last you a lifetime.
18.5" WSM, Hasty-Bake Suburban, OTG 22.5", "Antonio" Bandera, Mini WSM