Your current GK 4.3 software is a single denomination version. You can change it to multi-denomination by changing out the GME chips with ones that support it. G0002142 is one. That doesn't get you any new games, but allows you to be able to play more. You can set up to 12 games per denomination in the MD version.
You could get GK4.0 too, it has more slots and keno. You'd have to change out all your chips for it. Here's the games M0000531 GK4.0 has:
Bonus Poker
Deuces Wild Poker
Double Bonus Poker
Jacks or Better Poker
Joker Poker
ACE$ Bonus Poker
Bonus Poker Deluxe
Double Double Bonus Poker
Deuces Wild Bonus Poker
Double Deuce Poker
Loose Deuce Poker
Triple Bonus Poker Plus
ShockWave Poker
Keno
4-Card Keno
Super Keno
Caveman Keno
Top-Bottom Keno
3-6-9 Way Keno
2-4-6 Way Keno
Super Way Keno
Black Rhino Slot
Super 8 Line Slot
Diamond Mine Slot
Wild Flower Slot
Lion Fish Slot
Super 8 Race Slot
Blackjack
There are several different variations of GK4.0, but they have a mix of poker, slots, and keno. 4.3 is primarily different poker games. I think Samron Slots (NLG Username rjpohl) has some 4.0 sets for sale.