In the past few weeks I charge more then the usual maximum 30% of the Credit card limit.

I currently have one business card each for both of them through capital one that I got using personal guarantees but the credit limits are very low (1000 and 500 respectively)but I keep the utilization rate sub 20%.

So if the multiunit property is the SFH loan limit you should be okay to purchase but you will need to live in one of units.

Is it an LLC, a limited partnership etc...

They do not want to owner finance it and then new owner runs it into the ground and they have to take the property back worth less than when they financed it.You have to be careful on giving full guarantee on  a project if you have limited experience just to get into a deal with owner finance.

There's definitely cash flow ops, but obviously appreciation is pretty limited. 

If you only have a couple thousand in the bank, you're pretty limited in what you can do, unless you find the alternative financing options that so many on these forums discuss. 

If your are wanting liability protection. 

I would recommend you talk to @Tim Swierczek about financing options, most people finance their first property under FHA which is fine however it may limit your ability to expand. 

Electing S-Corp taxation is not a move to make to change liability exposure.