i. Term Limits: 12 years only, in any capacity.
1. Two Six year Senate terms
2. Six Two year House terms
3. One Six year Senate term and three Two Year House terms
Term limits may be a good idea (I have my doubts, though I'm not a fan of professional politician, either) but there is no way that they can be applied via statute, to Congress. Eligibility for congressional office is determined solely by the US Constitution. And that's exactly what the Supreme Court said last time the issue came up.
“Eligibility for congressional office is determined solely by the US Constitution.”
Term Limits Amendment to the USC.