With a business of flipping houses, you would be subject to SE tax if you were an LLC (page 1 income). If you chose to form an S-corp, then you would only be subject to the FICA tax up to the point of the wages the S-corp paid.
If this is a part-time type of operation, then you may have opportunity to have a lower wage base or set commissions paid to you for each house that was flipped.
If this is a full-time, sole income generator, then you will want to set a reasonable, but as low as possible, salary and keep the profits in the S-corp. The profits in the S-corp can be distributed as a non-dividend distribution which is not taxable and will not be subject to FICA tax.
If you have a full-time job and earn more than $94K+, then your income from this operation would not be subject to FICA because you would be over the limit and you can form an LLC.
If your spouse does not work and you do and earn more than $94K+, then you would not want your wife on the LLC documents because her half of earnings would be subject to the FICA (SE tax), but you would not because you had already hit the limit.
Confused??? It does get confusing, but you can save money and taxes if you are an S-corp, pay yourself a modest salary and the rest of the profits, which will be reported by you and pay income tax on, is not subject to FICA or SE tax.
Since rehabbing will be your business, I don't see this being investment property nor capital gain (short or long term). All the houses will be inventory and property held for sale to customers. All ordinary income reported on page one of the 1065 and subject to SE tax.
Example: If you flip 4 houses in one year and clear $30K on each one, then you have $120K income for the year.
LLC: $120K subject to SE tax and income tax on your 1040 would be $40,161, so that is $79,839 cash in your pocket for the year.
S-corp: $120K income and pay $50K in wages as salary. Your FICA taxes would be $7650 (1/2 paid by the S-corp & 1/2 paid by you from wages). Your income tax on your 1040 would be $25,624 for a total of $33,274. Net cash would be $86,726. You would have enough basis to cover your distributions so none of the cash that you pull out would be subject to tax.
You can set your salary arbitrarily low, say $500 a month and then in December pay yourself a bonus depending on how well you performed during the year (bump your wages say up to 25-33% of your net income for the year) and pay in additional Fed income tax withholding to cover all the estimated tax payments for the income you generated in the S-corp and you have full use of the funds for the year and saved some taxes.
Interview CPAs and maybe find some CPAs that have gone out on their own from a large firm or good sized regional firm. Do you have any contacts at banks that may recommend a good CPA. You can pay $300-500 for tax return guidance and prep, but you are going to get someone who will say just set up an LLC and be done with it (additional $7K in tax) or pay $1,500 for your business and personal return and you will get some advice like I have given and they will help implement your plan.
You do get what you pay for.
Joe