That set is a pretty old school so everything except maybe the Fafnir Scale and PDM could be swapped.
Some expensive items which are best now and give a ton of flexibility are
Costume Garment with Fixed Cast Time stone
Almighty Shadow Earring & Pendant
Some new items which aren't as expensive
Memento Mori (+10 all stats, 10% cast delay, 10% damage to size)
Guardian Claus (15% hp)
Beyond those expensive ones you could get some good upgrades with what was previously best.
Diabolus Wing (+10 all stats)
Splash Cat Hat (20% cast delay)
Excelion Shield or Illusion Shield (gives 10% hp/sp)
Malicious Shadow Set (gives some hp and hp leech)
Mysterious Muffler (gives agi up walk speed)
Speed of Light enchanted Temporal Dex Boots with a Temporal Ring (30% cast delay)
Imperial Glory (3% cast delay per 50 agi/vit)
Openair Headset (5% cast delay)
Hasty Shadow Armor & Shoes (set gives agi up walk speed)
If you can get your 0.5 FCT someplace other than shoes then these are great
Diabolus Boots (combo with D.Wing for tons of hp)
Fluffy Fish Shoes (20% cast delay, 20% hp)
Other cheap 'sidegrades'
Thanatos Hammer (hp/sp leech)
Can make armor and boots but might be a crazy amount of grinding.
Broken Cleaner Card is a great accessory card for DB. Get 2!
Research Assistant Bot Card is great if you can make a +16/18 Spear  or Pike .
My current setup is nearly complete and takes advantage of the flexibility the new OCP and costumes enchants give. Current 187 and taking my time making it to 200.
+9 Fafnir Helm - Bungisngis
Diabolus Wing - Kiel
Valkyrie Hammer - Dracula, Hunter Fly, Powerful Archer Skeleton, Polluted Raydric Archer
Excelion Shield - GTB
+9 Fafnir Breath - Deviling
+7 Rune Greaves
Jasper Ring - Faceworm Dark (need to grab the new card still)
Ring of Jupiter - Faceworm (need to grab the new card still)
Firebreath Shadow Weapon
Shadow Armor/Shield/Shoe is Malicious set
Costume Garment with Fixed Cast stone
Almighty Shadow set
Pet is Incubus for SP leech
Still working on this but the current plan for 200 is to have these stats
Short version, try to get the Fafnir/Rune pieces but otherwise a Memento Mori, 2x Broken Cleaner Card, a D.Wing, Splash Cat Hat, Excelion Shield, Imperial Glory or a cheap Guardian Claus, and a Thanatos Hammer (with hunter fly). Should be a breeze to level potion free with that.
Also for 150 to 175 your options are NCT or Illusion Turtle Island and I'd recommend turtles. After 175 go to Nogg Road or if you like being bored try the new GH map. At 180/185 try Odin4 and at 190 Abyss Lake 4.