As always - your car, your choices. Consider this in electing to ditch the factory air filter box:
- you'll be giving up the factory designed air horns in the air filter box;
- as you've stated, you're also giving up the natural connections for the flow guide valve and the valve cover hose.
- the new valve cover filter will eventually saturate with oil vapor and drip onto the manifolds, then you have to add an unsightly catch can.
The factory air filter box may not look sexy but it does a darn good job of what it was designed for. if you change your mind and keep it, block off the lower middle opening that connected to the air pump with a 1" rubber chair leg boot from a big box store.
Been there, done that. Just my thoughts that you requested.
Jim