Cash buy vs. bank loan

[Taylor Wade Wirthlin]

Would love the opinion of some more seasoned investors on this question. My husband and I are getting bought out of a company and should leave with about 300k after tax. We want to buy a home in Charlotte, North Carolina in the 225-275k range, but are debating if we should buy it in cash. We also have approximately 180k invested with a wealth management company, so the other option is to invest our buyout money with them and then they have agreed to loan us 50-75% of the money that we have invested with them (which would be approximately 480k) for a home at a 4% interest rate.

For more context, we can't qualify for a traditional mortgage because we are self-employed and do not have two years of work history yet. Also, if we did get a loan from our wealth management company our offer for a home would still be considered a cash offer since it is not a mortgage (or at least that's what we've been told).