Hmmmm..... quite a range of boards there on your short list.
How serious are you about "playing in small waves"..... until you can jibe and
water start, getting into waves is a little on the dangerous side. Mostly dangerous
to your gear and rig, as even small waves can take the board and rig away from you
and tumble them/pogo them/ etc.
Probably better to learn your jibes and waterstarts in fairly flat water (chop, even lots of it is OK here) then think about playing in the waves.
You are really a light weight, bo I'm puzzled that you found the 120 liters board (what board was this....>) hard to sail.
Here's the specs on the boards on your short list:
GO 122 122 244 71.5 46.7 TBA 5.5-9.0 Freeslalom Swift 400 S-Flex 32-44 Tuttle
GO 133 133 245 76.0 50.0 TBA 5.0-9.5 R13 Race SL 480 S-Flex 40-50 Tuttle
The GO boards only come in TuffSkin, so they are going to be pretty heavy compared
to the Kombat or Futura.
If you are beyond getting slammed over the front of the board and having damage on the nose of the board, then you may not need the added durabilty and weight.
Kombat 122 122 235 72 46.6 7.3 7.7 - 5.5-9.0 Freeride Flow 360 28-42 Tuttle
A very nice board, but will it be a good choice as "the next step" beyond the Rio
I'd like to think that you have the skills to use this board in small waves, but I think you'll probably need at least one more season for that to be a reality.
Futura 122 122 244 71.5 46.7 7.15 7.55 5.5-9.0 Freeslalom Swift 400 32-44 Tuttle
Futura 133 133 245 76.0 50.0 7.7 8.2 6.0-9.5 R13 Race SL 480 40-50 Tuttle
I've included the Futura here as it's really, in my opinion, a better board for a progressing sailor as you've described yourself.
Since you are so light, you may even want to look at boards in the 110 liter range.
Hope this helps,