Well, the motherboard is a mATX size click here (24.4 x 24.4cm to be precise), so any case that will fit a mATX motherboard will do. This includes mATX-only & mATX+ATX cases (any other case size will be too large or too small).
Next you need to decide the shape of case, depending on the space you have & aesthetics perhaps:
1. Tower, which stands upright: e.g. click here
2. Desktop, which lays flat on its side: e.g. click here
3. Cube, which is like a combo of the two: e.g. click here
The above are only examples showing the shapes available & are not necessarily purchase suggestions.
The missing hardware is an optical drive, & a music production (MP) calibre sound card perhaps. The latter would depend on how serious you are into MP & your budget, as these can be pricey. Another thing I would suggest is at least one additional hard drive for backups only. You don't want to slog for hours only to have your precious creations gone in an instant due to a hard drive failure. G