Your going out on an ex Thomsonfly aircraft and returning on an ex First Choice Aircraft
2G/H wouldn't be my first choice of seats on the ex Thomsonfly aircraft, they have the bulkhead in front of them and as such do not come with a foot rest, have limited leg strech room and if you are tall your foot reaches into the front galley, which gets knocked by the crew when having to move carts. 1A/B is a better alternative if you want to be in the front row.
On the return journey you will either be in 2F/G which is the 2nd row or they may put you in 1F/G if the computer recognises you have requested a bulkhead seat on the outbound. I personally would change the request to row 3/4/5 G&H they are all the same on the ex First Choice aircraft, but on the Ex Thomsonfly ones, these are better. 1F/G on the First Choice aircraft isn't a problem because the galleys are bigger and crew can avoid using that area if they have a tall passenger in the front row.