I'd highly recommend simplifying the grain bill first and foremost. Pilsner malt with some Aromatic malt as you see fit (could potentially be none, which is just fine), and leave it at that. Maybe some Munich or Vienna instead of the Aromatic, but that's about all I would recommend. If you're going the Tripel route add table sugar (NOT candi sugar/syrup, just plain ol' table sugar will do just fine), if you're keeping the ABV a bit lower (Belgian Blonde kinda range) go all malt lest any sugar additions dry the beer out too much. I'd also suggest going with a hop burst for your Belgians. No bittering addition, just lots of hops in the last 20m of the boil. Personally I find that approach gets the best results.