Talk to a broker in your area about how much that would be and then save aggressively towards that target.

However, those rents may be market, but if the tenant pays for electricity or water, you need to back that out of their rent (utility allowance).Tenants are not supposed to have a co-pay >29% of qualifying income and the voucher addresses the difference.For a small investor, I wouldn't target them since I stated the major rules, but there is paperwork if your property has a use restriction requiring income qual. 

My target tenant is also a sec 8 tenant and so I don't have to spend alot of time chasing rents either. 

I, on the other hand, determine my max bid not on the 70% rule but on my own Return on Investment (ROI) Target or Hurdle rate.  

I am thinking of targeting homes with parking or a garage as a must.

@Tommy McGraw Condos are good to put in if the target market will be buying them as a primary residence.

Given that you're brand new and will be living on site as well you may be better served to target an empty property.

I target C class markets and look for cash flow.

TI...aka Tenant Improvements...your future tenant may want to negotiate different terms for the move in, like a few months discounted rent(this could be on top of the above mentioned vacancy) while they build out the place, or some concession for the Tenant Improvements, if you  have an empty shell it could require extensive work to make it business ready for different types of business, think needing to add bathrooms for a gym(dozens of showers and toilets, lockers, etc) or adding a fully equipped commercial kitchen(walk in freezers, special fire suppression, a few extra sinks or drains) With apartments, I rarely have to do extensive build outs or concessions for tenants, even if I have full on renovation, it is almost always replace the old with same but new, ie tear out old kitchen put new kitchen in same place, same plumbing, just new cabinets, and flooring(if you are at all handy, you can do most of it yourself, or be able to estimate accuracy of bids easily).

The 3-5 year timeline is a little tight, but buying a fixer upper will help to hedge against that.Summary - Look at your target market every day.