poorowner- And when you get around to removing that popcorn ceiling, have it tested for asbestos first.... Here is a link that might be useful: Popcorn ceiling removal

#2 - insulated ceiling/air tight (IC/AT) is mandatory in many areas and always recommended if installing in a ceiling that is insulated, or should be. Most low voltage housings are only IC/AT if new construction type. Light shop was correct in recommending new construction. #3,4 - looking at attic for access does not mean that the housings will fit where desired unless they also carefully measured the layout to see what may be in the way of each fixture. The layout is generally done from below and projected up onto the ceiling with exploratory small holes to then locate in the attic. That the electrician found the space issues when starting the project should be foreseeable by him. How the electrician priced the project may reflect his experience. Low voltage new construction housings are generally larger and harder to place than non low voltage new construction housings. The fixture you ordered may be a brand or model he hasn't seen before. For example, Halo has a 3" low voltage fixture made for shallow depth but the housing is huge in length and width and can be quite a surprise if one hasn't used them before. If you don't need the shallow depth it is also a mistake to order that model. #5 - sounds like store does not stock the housings. Buying product that may or may not fit well from stores that don't stock and won't accept a return is risky. Electrician should try to put in the new construction. If you aren't in a mandatory IC/AT area then you can substitute remodel housings where necessary and at least limit the number you must return or eBay. And then there is the issue of why and how you ended up with the number and type of fixtures you are using but I'm sure others will add to the thread about that.

Good luck working through the existing can light hole with only 3 or 4 inches of clearance. This should have been addressed before the cabinet was installed. Better yet, after the old cabinet was removed but before the new one was installed. It is just going to make what would have been a simple job much harder than it needs to be. Sorry if it seems I am being critical. This is just a typical scenario where nobody thinks about the electrical until it is too late. Worse yet is when the customer then has the nerve to complain about the price being "higher than it should be".

Hi Everyone, I wanted to report back about what we ended up doing. We hired a drywall company and had the popcorn ceiling scraped off, and they then did several coats of 'skim coat plaster'. They did a great job and the ceiling looks great! It looks higher than with the popcorn. We are having it painted now, and then will repaint the walls ourselves. Our new kitchen cabinets arrive April 6th., so all should be done and ready for their installation. I am very happy we decided to remove the popcorn on the ceiling. Our rooms look larger, and ceilings higher, and not so dated. It was well worth the expense, and mess, and we were able to stay at a friend/neighbors house while they were out of town. Thank you all for your advice & input.