sounds good so far, your space is about half the size of what my tent is(5x5) which I built out of pvc pipe and black plastic. It was a lot cheaper than a pre-made tent and it requires a little bit of improvisation with mounting air circulation and stuff but has worked out nearly as good and much cheaper. If a pre-built assembly is what you want then it should be sufficient.

When those plants get old enough to start feeding nutes, you are gonna want to start LST to create an even canopy of bud sites. It's simple and a really effective way for growing indoors under artificial light. Basically by forcing the main stem to grow horizontally the secondary growth grow upright toward the light producing a top cola bud site. With that small of a room a Scrog grow would also be perfect which utilizes the LST method to precisely train your tops to be evenly spaced and a uniform canopy.

Either way, you should probably use one of these methods to efficiently use your light and increase yield.