My opinion, is a cabinet that is open in the front and the back...
In that way you can use the table from the back side or the front side by just fliping the fence around,,, for the big boards that need to have work done on them...e.g. cabinet sides.door panels, etc.
The MDF/PLYwood/PB/etc. is strong when it's on it edge...and can take on a big load easy.
Plus by not enclosing the router in a box it will run cooler and last longer...heat is the enemy of any power tool
You can make a cabinet that is strong with some 2 x 6 stock for the inside side base and to the support wheels to it so you move it around easy in the shop..
Below you will see the 3 types I like best ...after all it's not what's below it's what's on top that counts..and what's under the hood..
In may shop storage is at a big deal and I use the space under the top for that..
I should note many of the jobs you will do on the router table the chips will shoot off the end of the router table top, just the nature of the beast and the others will be sucked up by the Vac.pickup on the fence...or to say they should be...
The way most router are made they blow the saw dust up if they are mounted upside down in the router table...