I want to know is it more cost effective or easier to purchase the property alone and put it in a mortgage in our name or purchase the LLC from him that holds the property within it.

EDUCATE YOURSELF - yes, it will take time, but will lead to a selection that better meets your expectations & avoids potentially costly surprises!

If your property management company is good and has built an internal maintenance team which has set rates and had strong relationship relationships with licensed contractor which should keep costs in control, you should never need to shop contractors on your own I wouldn't think.So in short, our policy is give us your preferred contractors upfront if you have them, but then we work all tickets to resolution including dispatch, and payment of invoices.This is of course for operational expenses.  

I hate to go that direction, but their negligence has cost us thousands.

Aside from downpayment, you want to have a solid emergency fund in place, something that can cover unexpected repairs, vacancies, or any other random costs that pop up.I’d also recommend saving more than you think you'll need and keeping a close eye on your expenses.

Security Deposit: 2600Lease states no smoking/painting walls/no hanging things on wallsTenants have moved out and have left two truck loads of garbage to be removed.Damaged doorPainted walls which got on the ceiling and trim Lots of holes on the walls throughout the houseDamage from windows being left open constantly Weed was clearly smoked in the house (smell throughout the place) so we need to deep cleanWater bill wasn't paid so I had to turn back on utilityMissing keyQuoted costs:$450 junk removal (some furniture)$935 for damaged doors/windows, painting cleaning$30 for utility turn onTenants were only there for a year before moving out so a lot of this is beyond normal wear and tear. 

In the beginning I want to manage by myself to save cost.

If you own 25% or more of any LLC you are required to register with a FINCEN ID for beneficial ownership by January 1st or you could be subject to $500 per day fines.Have you taken care of business?

Based on my experience of running properties, even if the build were to cost you as much as $600k but you could generate $125k/year, you'd be very happy with that investment. 

The rates are high right now but these loans are limited based on cashflow so you cant take a loan that costs more than you're receiving in rental income.