Ziprent will write the lease, execute it, then get the tenant in the unit and collect first month's rent and deposit.

If I were in your shoes and you wanted to keep them on MTM I would have them still sign a MTM lease and make the one resident pay a deposit, assuming you can sign new MTM leases in your area.I personally would still probably shift them to longer-term leases anyway, but it's not a bad idea to feel them out for a few months.

I also let him know that I would need 3 months of bank statements showing deposits going into his account from the business.

It can be a huge pain to get started but you do get your rent direct deposit every month.

Also, is he entitled to the security deposit (minus any repair expenses)?

And this is CRE, so it's cutthroat, it's no one's problem but your own if you lose an earnest money deposit. 

Should I have them pay right now or out of security deposit whenever they move out? 

Which is why there is more investment in real estate and bank deposits  in the “western world” (which includes.

If a buyer is coming down with a high-down payment and quickly making a large deposit into escrow fighting tooth and nail about proof of funds may be a red herring.Credibility is also a factor here.

Others will collect first, last, and a smaller deposit.