Since your new, I'd strongly suggest that you goto your local apple store if there's one close by and touch & play with the models your interested in. Find a manager or two and ask them of the problems there experiencing with different models , if they say none , throw in some I heard this and that , talk to the genius's that diagnose and fix the problems in house.
Do not take what you read on the internet as being 100% true. Its best to do YOUR OWN research and go from there. Apple has a 14 day return period. If your doing a build to order well that's going to add to you getting your new computer.
As for the MBA, I personally can say that I never had problems with it connecting to the cable modem here in house or any other location that I was at. There are lot's of contributing factors to consider also.
If your going to be coding I would strongly suggest 8 gig of ram, the I7 for some is an overkill, and allot recommend the I5 instead. SSD size well that depends on what your planing on storing. Do you plan on keeping this for a long time? If so you mite want to go with a maxed model, which I know some stores carry, it will not show up in the online store either. Our local store carry's the maxed put 13" MBA, but does not show in the online store
Good Luck