Dude you have a pretty archetypal bag there.
Definitely don't spend any more money on plastic - you'll get way more mileage out of using the money to golf more, get a nice bag/towel/water bottle, have a beer after a good round, etc. If you absolutely need to get a new disc, which I often fall victim to myself, get another Teebird or Leopard, maybe in a different weight or plastic. This way you'll get to learn the variety you can get in one type of disc, and if you lose your Teebird or Leopard (I've lost my share myself), you'll have a replacement. Trying different putters is always fun too, I don't often lose them and they're very versatile discs - they can be used for drives, approach shots, and of course putts.
Don't forget to put your phone number or email on the bottom of your disc, if you're comfortable with that, in case it gets lost. I've gotten quite a few discs back and met some nice people that way, but I happen to live in a very disc-friendly area.
The Teebird/Leopard combination is solid gold and used by everyone from beginners to pros. Some people use Eagles in varying weights/plastics/wear levels, but in general you can do just as well with either method.
I personally use a PD instead of the Teebird, but honestly it's because I have them already, I could buy a DX Teebird off the shelf and likely do just as well with it as I would with a PD. The River has a lot of variance I think, I've seen them compared to both Leopards and Eagles, so you're probably best of staying with the Leopard and maybe trying different plastics and weights if you lose it or find yourself considering replacing it.
Wizard // JOKERi // Anode // Fuse // Axis // Vector // Firebird // Amp // River // PD