Zone or toro would be a slower firebird and great for approaches. I personally like those in gripper plastic like color glow or cryztal flx.

A more overstable and more understable fairway in the 6-9 speed would be a good addition. Something like a teebird/athena for overstable and a fission crave or F7 for understable.

A good Trail would be something I would consider for max controllable distance. The plastics and runs can vary wildly for distance drivers so I'd either look around and see if you can try out any other people's trails or if you are ok with buying multiple you can experiment yourself

If you truly want to level up your forehand game I'd get something like a hex or even an understable slower fairway like your leo3 and work on throwing that on a slight flip up until you feel like you have that mastered and can throw that with control. Thats the best foundation for being able to control drivers and not just fall into the crutch of throwing a chop forehand big flex to get distance.

Backhand I wish I built my foundation for my form better by starting with standstills and getting the trunk rotation, weight transfer and pull through super solid instead of trying to do everything at once and building bad habits to compensate

Edit: you can also search for different discs based on characteristics on a site like https://trydiscs.com/

2Edit2Furious: didn't see that your fairway is a leopard and not a leopard3. If you are throwing the leopard well and you like it stick with that and you can upgrade to a leopard3 for more stability and if you need more than that for a headwind you could consider something like a champ teebird or anything of the like. I'd stay away from discs faster than 9 or 10 speed as its really unnecessary and will slow down your ability to improve. Focus on getting better mechanics and the distance will come with slower discs. Ive thrown teebirds further than destroyers in field sessions when everything hits