Aion-3.0-Mini and Solar Pro 4 are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
Aion-3.0-Mini, from Aion Labs, has a 131,072-token context window and is priced at $0.70/M tokens input, $1.40/M tokens output on OpenRouter.
Solar Pro 4, from upstage, has a 524,288-token context window and is priced at $0.03/M tokens input, $0.12/M tokens output on OpenRouter.