Let me start with your last question regarding whether or not to show a profit as this is a very important concept. When you are building a business plan you really want to understand the financial model under various scenarios to try to capture the worst and best case scenarios on both the revenue and expense side.
I don't know what type of business you plan to launch but you should have a very strong understanding of the revenue growth rates in your industry and market size in order to run scenarios on how fast or slow you will grow.
On the cost side of your financial model, it is extremely important to understand how much startup costs and recurring costs (admin, marketing, accounting, operations, etc.) will be incurred while also achieving profitability. Then there is the time factor. Your business will go through stages of growth like all startups so being able to model your company's progression over time is critical.
When you ask, should I be showing a profit? The answer is really something that only you can answer since you are the one that should understand all of the revenue and cost scenarios of your business.
Yes, there are some predictions involved in building a financial model and you may be wrong, but you need to try as best as you can to understand all of the revenues and expenses to determine when you should be showing a profit.
Now back to your first question. From an accounting perspective, whether you show a salary above your profit line or take profits below is somewhat dependent on the type of business entity you are forming and the partner/member vs. employee relationship that you have with your wife.
For instance, if you chose to incorporate as an S Corporation you would be required (per the IRS) to show a salary that is reasonable in your industry above the profit line, even if both you and your wife are corporate officers.
If you are not going to incorporate, whether you pay yourself a salary above the profit line or take a distribution doesn't matter since you and your wife would receive a k-1 and report the income and expense on your tax return.
On a side note, if you don't incorporate, you and your wife may be subject to double self employment tax unless you decide to treat one spouse as an employee rather than a partner.
I wish you luck with your new venture with your wife and remember to constantly update your business plan--it should be a living, breathing document.