Guys and gals coming on board in the future, first off welcome aboard. Great company and a good time to join.
Narrow bodies in general will give you the quickest upward movement. Of the narrow bodies, the Mad-dog or Mad-puppy (717) will give the quickest upward movement for the most part. In NYC, upward movement is super fast on all narrow bodies. I came from a regional and was used to doing 2 leg commutes for years. It wasn't that bad at the regional with some proper planning. I was NYC based on 717 initially and let me say, my 2 leg commute was easy barring weather in the northeast. At Delta you can reserve jumpseat 5 -1/2 days in advance going to work and 3-1/2 going home. If you commute thru ATL to NYC, there are tons of flights. MSP to NYC is easy for most part. Not sure about DTW to NYC. Point being, NYC is not bad other than commuting in day b4 and going home mostly the day after. That part sux. Plenty of crashpads to choose from.
You should be able to hold ATL on 88 or 717 or 73N within a few months. I held ATL 717 before I started sim training but didn't convert to ATL until this month. I was awarded ATL in November during training. 2 months in NYC. 2 months during winter weather and I had no problems 2 legging it. Maybe lucky!
Food for thought. If you don't want to do a lot of training jumping from fleet to fleet in your career here, if you get A320, it's a perfect 1st step to A330, which could be a step to A350 one day. Easy transitions.
Don't worry if your only option is NYC initially, it's not that bad if you take the time to plan your commute ahead of time. (Barring the weather) Plus, plenty of open time to be had. If u want to sit reserve any base and not fly much, well, I'd look for 73N or Airbus right now. But that's always subject to change. Again, welcome aboard to all newcomers.