Ok, so the first thing you need to know is that metallic reloading (stuff with brass cases) and shotshell reloading requires completely different gear. Some of the accessories cross over (like the powder scale), but most of the stuff is fairly specific to either type.

Secondly, I think that you're getting a little ahead of yourself and trying to overanalyze this a bit. The first step is to simply figure out where you want to start (metallic or shotshell)

My suggestion would be to start handload for that which you shoot the most of dollar wise. In other words, if you shoot 4-5 rounds of trap every weekend, but shoot your pistol/rifle every couple months, then start with a shotshell reloader setup. For that, look into the MEC presses and kits. You can buy what is pretty much aready to go out of the box setup for the gauge of your choice. I reloaded shot shells for trap shooting as a teenager on a MEC press and it was pretty easy to do if I recall (I haven't reloaded shotshells in years, though).

If you shoot a lot more rifle/pistol ammo by cost, then a metallic reloading setup is probably the best start. I strongly recommend the RCBS Rockchucker Supreme Master Kit as a initial starting point. For just a little under $300 you get pretty much all you need to get started loading metallic cartridges minus the components (brass, bullets, powder and primers). There are a few additional tools to get that don't come with the kit, but for around $400 you can get what you need for at least one cartridge. Once you decide where you want to start, then feel free to post any specific questions here. There are lots of very experienced handloaders here that will be glad to help you.

Mike