If I am going for a home defense gun size won't matter so much.
Yep, if you are looking for a home defense gun, get something like a midsized .38 or .357 to soak up some recoil and be a bit more manageable. Unless of course you are looking at auto's, but it sounded like you are looking at revolvers.I won't feel comfortable carrying concealed until I am VERY proficient at the range, so my first gun will probably be something large enough to not kick too much.
Hard to beat a model 10, 64, 19, 66, 586, 686, Security Six, GP-100, Trooper Mk III....... Remember, you can shoot .38's in .357's, and you will always have a power choice. I download .357 brass to shoot my .357's all the time. Just shoot a little bit of full power .357.
Auto?.....Try an standard XD in 9MM. Very simple to operate (like a revolver), which is a good thing in a crisis, accurate, & easy to shoot well.
When you get proficient with a medium sized gun, then you can get a smaller, lighter, heavier recoiling one to work on, and ultimately carry. That said, plenty of people carry medium and full sized pistols.