I go to the Deals forum for advice. Many more knowledgeable people. https://discuss.cakewalk.com/index.php?/forum/34-deals/ But FWIW:
There are five main tiers: $299.99, $149.99, $99.99, $79.99, $49.99. Stealth Limiter is $124.99, so it's between two tiers. Something at $149.99, if you can swing the extra $25, would give you a much wider choice. Sunset Sound Studio Reverb, for $149.99, receives high praise at the forum and good reviews elsewhere. That would get you anything on the $149.99 level, including either edition of T-RackS 5, or both. Stealth Limiter too, obviously.
I love MODO Bass. The full edition is $199.99, but the SE is $149.99. I'd get the SE if I didn't have the full. I plan to pick up MODO Drums SE, also $149.99, as one of my freebies.
I'm not trying to upsell you, just want to explain what the extra dosh could buy.
If you buy in with Stealth Limiter at $124.99 you'll have plenty of options. You could choose individual modules from the different flavors of T-RackS. Each is $124.99 or less. Also on T-RackS, some strong recommendations for their Tape Machines, at $99.99 each. Some of the Signature AmpliTube collections at $99.99 each sound great and are recommended by forum members. I think I've seen the most praise for Orange, Hendrix, and Brian May. And you'd qualify for Syntronik Deluxe Upgrade, but upgrade from what I don't know. Syntronik Full, I imagine, which runs $199.99. If you have that already, the upgrade might be a good deal. If it's an upgrade from Syntronik Free, even better.
BTW I think if you have JamPoints you can apply them, to lower the price of whatever you buy to qualify.
The Group Buy is at 20 free, maybe to reach as high as 24, and extended through October, so you have a lot of time to consider. There's chatter - no idea if it's based on anything solid - that IK might add to the list of available freebies, so I plan to wait to make my choices.
Hope that helps somewhat.