To give my two cents (and feel free to take it with a grain of salt), a project like this is something you really don't want to cheap out on. Sacrificing good quality parts from the get go sets you up with a rocky foundation to work with. If you cheap out on your building blocks, you're very likely to be unhappy with the end product. I understand that, at a young age, it can be difficult to get the kind of funds needed for this kind of project (around the $400 mark), but if you really want to end up with something that you are happy with (and something that will last you a long time), saving up for the good stuff pays off tremendously in the long run. I've worked on G-Boys, Ashidas, and lesser-quality builds from people like PortaPackIt and PhoenixRetroMods, and I can tell you first hand that the difference is night and day.
In addition to the price, building something that's already been developed / perfected like the Ashida makes the entire process much simpler than trying to design something of your own. That's not to discourage you from making something of your own - it's great to learn those kinds of skills - but if you're looking for something simple, the Ashida is absolutely the way to go right now.
TL;DR save your money, buy nice or buy twice!