The husband and I recently bought our first house and know very little about stuff :) The kitchen came with a Jenn air electric cooktop (1990 or older) and a Jenn air radiant oven (same age) The oven was under the cooktop. I wanted to replace electric with gas, so I started doing some research and getting quotes. Long story short, the oven had to come out of there for the gas line to be run. Right now, the cooktop and oven have both been taken out. I plan to put a gas cooktop and a cabinet underneath. I have a few questions :

should the cooktop go in first? or does it need to be supported by the cabinet somehow? Also, while we were taking the wall oven out, we managed to break the granite strip that was seamed into the counter . It cracked in the middle and broke into two. Is that easy to fix? What materials should we be using?

When I go about getting cabinets, what should I look for? I have the cut out dimensions so I will be sure to take those to the store, but is there anything else I should keep in mind?

Any and all advice will be appreciated! Thank you!