I would definitely not recommend this.

Has anyone ever use them or is there another company recommended?

I recommend that you have a PM in place before you leave.

I have some clients that are interested in looking at Condo/Townhouses in Houston as an investment, but I'm not sure what to recommend they withhold as Cap Ex from their cashflow when running the numbers.

If this will be your first property, I'd recommend not making it a section 8 property at first.

If you can find a duplex or 3-4 unit property that makes financial sense with the necessary down payment and reserves then that would be my recommendation.

We work with many Canadian investors and have some good CPA recommendations for you should you need them. 

This allows them to tailor their search and recommendations to fit your specific investment goals and criteria.6.

But the example you gave, I would estimate $3M as a good starting point for the project.Your post liquidity also will be looked at as well.I would recommend partnering with people that compliments areas you may not be strong at for your project.

Utilities, taxes (property, local vacation, & income), landscaping, furnishing / decorations / amenities, pest control, & supplies (soap, TP, etc) are the big ones on my STR calculator that you didn't mention.I'd also recommend using the enemy method to determine expected income.