Mid-towers have tons of room for standard ATX builds; for the mATX build I suggested, you'll have ridiculous amounts of unused space for airflow and room to grow. Technically, the cases I posted are bigger than you'd need but I don't like recommending smaller cases as they kind of stifle your upgrade options down the road -- moving to a full ATX, multi-gpu build, for example.
The cpu cooler will be a tight fit but that's common and by design; the cooler's fan should be in-line with the exhaust fan. I haven't built in the NZXT, but the Corsair case I posted clears 160mm heatsinks with no contact. I expect the NZXT to be the same as almost every mid-tower is designed to accommodate these types of coolers.
Specific to the two cases I recommended, you'll probably want to switch/add a couple high-static intake fans. Cases with obstructed intake slots are quieter but usually ship with woefully inadequate fans. Again, I can't comment on the NZXT but this is definitely the case with the Corsair -- especially if you have fully loaded hard-drive cages. I use
these because they're pretty but there are better (but
uglier 
) options out there.
Anyway, you should probably look at
all the mid-towers now and pick one that you can live with through multiple upgrades and rebuilds. I'll list some final notes to consider for longevity:
- Make sure it can handle 160mm cpu coolers. Almost all will, but it's better to be cautious.
- Make sure it can handle a top-mounted, 240mm radiator (2 x 120mm fan mounts) -- in case you decide to upgrade to an AIO water-cooling solution.
- Make sure it can handle a standard ATX board without clipping the psu -- anything at least 17 inches tall is usually fine.
- If the case has side intake slots, plan to upgrade to high-static fans. This is technically optional but necessary, in my opinion.
