I’ve not flown either cabins but from what I hear, Etihad is excellent in business class where as Gulf can be quite hit and miss regardless of cabin.
Regarding your seat configuration, if you’ve booked it already, you should be able to access what aircraft you are flying on (subject to changes). Jump onto http://www.seatguru.com and have a play around there to see what is good and what isnt.
If you have to fly via the UAE, I’d recommend Qatar over all of them as it is a SkyTrax official 5-star airline has recenlty won the best Middle Easter Airline award. Alternatively, why not go for Paris-SIngapore-Bangkok with Singapore Airlines – best airline in the world as well as best business class. Alternatively, fly Cathay Paris-Hong Kong-Bangkok first class – another 5-star airline and best first class product in the world. Last recommendation would be to fly direct with EVA – they are meant to be a superb airline as well (recently won best Premium Economy carrier).
Let me know if you need more info.