I have a Garmin 225 and it would suit your needs. Not the absolute bottom of the barrel Garmin, more of their midlevel watch ($200-$250 price point when I bought it a couple of years ago).
The start/stop button is at about 1:00-2:00 spot on the watch, while the lap button is at the 4:00/5:00 spot, so there is plenty of distance between them and they are easy and intuitive to deal with after just a few sessions.
The advantage of some of the mid-range watches over some of the entry level watches is that you can switch between two different screens with different fields of data. So unlike some watches that I used in the past, I can toggle between a screen that shows total time and distance (which I like to use on easy runs and tempo efforts since I am seeking to run for a specific period of time, but is not so useful for me during track sessions because it makes figuring out my interval times a problem) to a screen that shows lap time and distance with just the click of one button.