I live 100 km from Namur, but every now and then we go out mtb-ing in that area.
-Are you in a group of 4 or rather 400?
What kind of biking do you wanna do? (Trekking (in need of panniers?) one day trips ( race type or tourist style) ,...)
-Are you a beer expert? Although not a smashing experience, there's a brewery you can visit +/- daily within cycling distance from Namur (on top of a hill :~))
Best beer doesn't exist, my selection out the 500 or so:
Chimay ( and their cheese!)Triple,
Hoegaarden St Benedict,
Hoegaarden Grand Cru,
Mort Subite Kriek
Corsendonck( and their cheese!),
Maredsous (and their cheeses!!) ,