My business is set up as S-Corp with myself as the only W2 employee, and my wife as a 1099 contractor.
I am 47, my wife is 51. I have a traditional 401K from a former employer (from a while back).

Researching my options, I found Solo 401K and SEP IRA appealing for different reasons.

With Solo 401K I can borrow, and it allows non-traditional investment. Both of these features are important to me.
But with SEP IRA I can deduct my contributions as a business expense, which I understand I cannot do with Solo 401K.
Please correct me if I am mistaken about any of this.

With this in mind I am considering the following strategy:
1. Roll over the old traditional 401K to a new Solo 401K
2. Make new contributions to a SEP IRA, taking business expense deductions
3. Later roll over SEP to the Solo 401K, making the funds available for borrowing and non-traditional investing.

Does this make sense? Am I missing anything? Are there other alternatives that may meet the above objectives?

Thanks
-Art