I've seen Duvel clones that use Styrian (similar to Bobek) and Saaz, like this one (not sure the batch size, looks like maybe 10 gal by the malt bill):
15 # Durst Pilsner Malt
1.5 # Belgian Caramel Pils Malt
1.25 # corn sugar (dextrose)
Mash with 3.5 gallons of water to achieve 132 F. Rest for 20 minutes. Step up temp (via water additions or decoction) to 158 F via 3-4 steps of 15 minutes each , with 15 minutes rest. Hold final temperature for 1 hour. Sparge with 4-5 gallons of water to collect 6.5-7.0 gallons of wort.
Boil for 60 minutes. Add 2oz of Styrian Golding hops at the beginning of the boil. Ten minutes before end of boil, add 1oz of Czech Saaz hops. At the end of the boil, chill aerate and pitch with White Labs WLP570 Belgian Golden Ale yeast or Wyeast 1388 Belgian Strong ale. (If not using a starter, doubling your pitching rate is recommended.)
Ferment at 74-76F. Note that the recommended ale yeasts tend to slow down as they approach terminal gravity. Occasional "rousing" of the yeast can help fermentation.
Note: Beer starts to "peak" at about 4-6 months of age.
Target O.G.: 1.072
Target T.G. 1.010
Expected ABV: 8.5%
However, if it were me, I'd make a Northwestern-style American Pale or American Amber, or even a North-German Alt style (think Alaskan Amber Ale).
Couldn't really find an actual Slovenian beer I thought was interesting enough to brew, but you could also look into that.