Okay, back for a second round of slightly more narrowed down questions. The thought on Mugo Pines? Will they backed well and eventually form a dense, full canopy?
The thing about Mugos is I know they are at several nursery places around me. They wouldn't be hard to get, so it'd be a secondary option- or one if my wallet allows me to chose more than one attempt. Also know they are more naturally bushy and dense then normal pines and my initial thinking is that habit would lend well to something that bud back well...but I'm a novice for a reason so that assumption could absolutely 100% wrong.
Mugo pines are awesome, but they take a lot of patience and a bit of a specialized approach. I found them to be not as vigorous as scots pines, but still pretty solid trees. It takes a while to get the hang of them, and they can make very rewarding bonsai - in a period of 6-15 years.
On the resources page of the forum, there's a compilation of Vance Wood's advice about mugo's, there's also the mugo train thread which is worth a read.
The drawback of mugo, compared to
most other pines, is that relatively speaking, they don't take insults very well. I can strongly recommend to go for a more flexible/versatile type of pine, but then again, mugo's are cheap and there are plenty to be found. So killing a couple isn't that big of a deal.
Other pines just develop faster in my backyard. With mugo's I can apply one technique every year and they really need the rest and relaxation the rest of the year. Results can take a year to show themselves, so if you didn't perform a technique perfectly, you've just "lost" a year. For me, that's a major drawback. I have five or six of them, but they're mostly a 2-hour-a-year playthingy and spend the rest of their time sunbathing.
Other pines just recover faster, which is good for a beginner; they show you what you did right or wrong within 3 months.
There are some mugo fans and experts that are likely to disagree with me, either because they have a better climate or because they have better care habits than I do, or just because they're better at bonsai. I lack the patience for mugos, and I'm well aware of that.