Qwen 4B and 9B should be faster and better reasoning than Gemma 4 E4B. Other good options for that much RAM are Gemma 4 12b and 31b. Gemma 4 E4B would be better for native audio, but OP is using Whisper for STT so prob doesn't matter

The issue is not RAM size. It's memory bandwidth!

The 12B and 31B models will be useless on a Pi 5; maybe the 12B can be persuaded to run, but it may not manage more than one token per second. It only manages 17GB/s memory bandwidth (I have seen a suggestion that the 4GB model manages more).

But yes — some sort of small reasoning-oriented model (Ornith?) seems a better candidate than Qwen 35B.

(Don't get me wrong, I think the 35B model is ace… just seems like at least an unusual choice here)