Hi paisley,
What type of mattress do you have? Knowing more details about the mattress and the specific symptoms you are trying to correct with a topper along with your typical sleeping positions and body type would be very helpful and probably the best place to start.
It may be possible that a different topper can work better than you suspect and with your very light weight a softer ILD or even different thickness may also be worth considering (depending on your specific experience on the mattress and mattress / topper combination).
Without reference points that include your personal experience on the mattress and the mattress / topper combination it isn’t really possible for anyone to even make a meaningful guess about which mattress may work with the topper you have. The most effective approach is generally to first choose a mattress and then use the topper to fine tune it rather than the other way around so your circumstances are much more difficult to predict.
There are some topper guidelines in post #8 here that may also be helpful
Dreamfoam also has a pocket coil mattress here that includes 2" of 19 ILD talalay latex that is in your budget range (although I’m not certain of all the layers or if there is any other foam in the mattress) and it may be well worth talking to them about it.
Phoenix