You are on the right track. From the information you provided it sounds like your focused more on the investment aspects of the purchase. I like it. As an investor, your goal should be to maximize your return on investment (ROI). Jim is steering you in right direction. Buy it as an owner occupied tri-plex and rent out the other two. Why? Lower down payment and lower interest rate will offset the depreciation benefits. I can elaborate more on some of the other benefits offline.
I have a background in finance and an MBA from San Diego State. I work with lots of investors to help them find the best properties, negotiate the best deals, and provide them with superior financial analyses. My fees are paid through the real estate commissions when you make a purchase.
Reach out to me if you would like some help.
Nick Rhea, MBA, Broker
Bombora Investments, Inc.
I created a great spread sheet that answers your exact question. Its a great tool to play with numbers and see what they are "actually" are.
Send me an email from my site and I can send it or go over it with you...
My references are avialable upon request.
Ruben Sanchez: License REALTOR-BROKER 619.251-5093