I'm currently using something which I think was called Maxim, it comes as powder in a big dark blue bag, and I find this isn't too sweet, or have much taste at all, other than whatever I add. I think you can also get gel pouches, although these were pretty sticky.
As for the chucking up, if it's only a problem when you train indoors, hopefully it won't be a problem running the half marathon? Evn if it does happen, while somewhat embarassing, I think most runners realise that it can happen (apparently some quite well known Kenyan did it at about mile 23 in this year's London Marathon), so you're in good company!
Hope you manage to avoid in anyway, and best of luck come September and the half marathon :o)
Iain