If you're unsure, it's always better to be conservative and well prepared.

The home has $100k in equity so my first choice was to just expand that line of credit which would give me enough for purchase and rehab and then I could do a cash out refinance on the new property and pay off the HELOC.  

Here's the numbers:Single family house in NE San Antonio. 1,456 square feet, 3 bed 2.5 bathPurchase price: $105,000Rehab; $20,000Hard money loan: $112,500Cash out of pocket (From HUD stmt):$12,500 (down payment)$2,250 (points)$385 (lender fees)$892.50 (title fees)$1,320 (insurance)-$2,001.34 (credit for unpaid taxes)Total: $15,346.16Actual rehab cost: $19,678.12Hold time until rehab and refinance complete: 98 daysInterest expense: $3,020.55Refinance loan terms: 30 year adjustable rate mortgage at 5.75% interest fixed for 5 years at 85% LTV and 1 point.Appraised value: $164,500Cash-out refi amount: $139,825Cash back in my pocket after lender fees, title fees, down payment, interest expense, insurance, etc are all accounted for: $5,389.50Now the place is rented for $1,200 a month and I figure I'll pocket about $200-$300 a month after expenses and mortgage payments and in the end, no money tied up in the deal!

I don't know what kind of property you have in mind but you will be fairly limited on LTV and rates that isn't going to vary much from what you could get on Alternative Funding. 3) I would highly suggest you prepare for a purchase using whatever financing method, but then offering a NNN/option with the same amount being offered as a down payment.

If you have discretionary cash, lines of credit and 401k borrowing for plenty of quick cash, what is the top strategy to put them all to work?

Credit score will weed them out alone. 

If the tenant doesn't pay enough money to cover both rent and garbage by applying credit to the garbage first he will be short on his rent, making him subject to late fees and eviction for non payment of rent.

I currently have a few units and I'm looking for an experienced manager who is accessible and bilingual (Spanish) to assist mostly with communication, enforcing rules, inspections, tenant screening, rent collection and move in/out preparations and evictions.

To get the exact address I have to register for a free trial and it's asking for my credit card info. 

Preparing the property for rental.