I would have thought if you came with significant 737 experience they would put you on the 737. That's just my thoughts though and not the official company line. I can't see why they would put you on the 757. Remember also that just about every man and his dog who joined on the 737 and who are therefore more senior to you will be bidding for 75/767.
If successful can I request to be positioned on the 757/767 fleet
You can request what you want by way of the base bid which you will complete if successful. Trouble is they will make the job offer on the type and at the base where they need you/ want you. As soon as you join though you put in a Standing Bid for your base of choice and then it is in the lap of the gods as to when you get that choice, which depends on those more senior to you and their choices, fleet expansion/ contraction, current numbers at the various bases etc etc etc. Nothing guaranteed and if you put Gatwick 75/767 and they place you on the 737 you could be waiting some time as I understand it is over subscribed. Remember that Thomsonfly want you to want to join the company more than to fly a particular type.
How is roster with 737? More nights at home or more work than 757?
Read the earlier post with regards to Carmen rostering which will (supposedly) be in by the time anyone applying now joins.
What kind of standby procedure do Thomsonfly use?
We do block standbys, which you can bid for, but very few people do. If you bid you are pretty much guaranteed to get the block (1 week), the advantage being that you get 3 days off wrapped around each end of the block and you know you have these months in advance of roster issue. There is NO airport standby for pilots, you just have to be within 90 minutes (I think) of the airport, so go shopping or gym or whatever else and just have your mobile with you.
PP