Hi swampymc8 and Welcome to our beginners section!
I find that it's just different for every individual hobbyist. Some find a set of collected things in a tank kit that they will be happy with for their start whereas others find that parts of the kit just don't match what they want.
Personally I find that I really enjoy researching and choosing the individual pieces of equipment after I've learned more about them, but this does drag out the time quite a bit. In my own case I consider it to be all part of the same pleasure I get after the tank is going, so it doesn't bother me. Of course it never ends, whatever you finally decide to get, you will still learn things later that might have changed your mind had you known them but you just have to accept that.
Keith is probably right about the Roma kits, I hear a lot of the UK people saying positive things about them. And seems like I've heard positive things about aqua one kits but in both these cases I've not even ever seen one in person, so I'm not much for info.
The art of learning how to make good stocking plans can take quite a while. Many of us here feel a good time work on learning those things is during the weeks it can sometimes take to fishless cycle a new filter and be sure it has been turned into a qualified biofilter.
In making stocking plans you have an overall limitation in that any given tank will only be able to reasonably support a certain amount of fish, given its effective water volume, its surface area and the kind of equipment hooked to it. Additionally, there is the consideration that as beginners we want to leave some leeway to have a good experience with our first couple of tanks during our first couple of years so that we have a sense of what good baseline fishcare is before beginning to take greater risks.
This overall stocking limit is a parameter that is kept in mind all along while trying to juggle the other stocking plan problems: many, many species require that minimum shoaling numbers be kept up (eg. 6 tetras for instance.) This is because going much below that for very long will cause real stress to the individual fish, often resulting in disease or problems (they are often used to being in quite large shoals in nature and it very much a part of their physical being and instinct.) There can also be other sorts of "within species" number considerations and certainly numbers of divided by sex in some instances. Then there are concerns about species-specific tank needs like minimum tank height or tank length (these are fairly rare but do exist.) After that comes issues of which species work with which other species and which don't. And which species change character when they get older - that's an issue sometimes. Cost and availability is another obvious issue. And the general characteristics of your tap water can be a factor that many experienced aquarists take into account early on in their planning.
Now all of this can make it sound ridiculously hard to make a stocking plan! But in truth there are mostly just a set of somewhat arcane but finite little rules that many aquarists call on when deciding about stocking and there are lots of great members here who will hopefully come along and share these with you at your various stages of decision. Likewise, a little hard work on your part to do web searches on each species and read several descriptions about keeping the species will help to give you various tips and to formulate questions you can ask here on TFF.
Hope this gives you a few ideas about how to think about where you are going.
~~waterdrop~~
