I think the refs for glock or m&p are solid.
If you’re budget conscious, a huge benefit of those guns is the wide variety of aftermarket parts which means you can get stuff like holster, mags, sights, etc at a better price or with less effort to procure. I’d search the forums or start a post here if you have questions about specific gear, as often I see other gun forums promote frankly unsafe, subpar and ultimately overpriced gear.
Secondly with regards to the FFL question, sometimes you can get good deals online net of shipping and the FFL transfer fee. Especially if you get a good price on LE trade ins that often are carried a lot but shot little.