Just completed Inspection for 1920s home and freaking out

[Abi O.]

Hello -

I am a first time homebuyer and I am currently in contract to purchase a 3 family home in NJ that was built in the 1920s. I just completed the inspection yesterday and it seems the roof will need to be fixed(over 20 years, the boiler system is very old(there are 3 boilers), one of the 3 hot water heaters(HWH) is leaking and the 3 car garage (which is one of the main reasons the property is compelling as an investment purchase) is not structurally sound and may need to be demolished. Outside of those issues, the house seems pretty decent, is in an up and coming neighborhood and the rental income will cover monthly expenses (M/I, Taxes, HOA+Utilities) comfortably. I do not plan to sell this house within the next 5-10 years unless circumstances call for it so I am basically planning to buy and hold for the long run.

I am hearing that all of this work could be well over $60K ($25K for garage, 20K+ for  3 high energy efficient HWH/Boiler combos, and $15K+ for roof)) which is causing me great concern. Main reason being, I had planned to renovate the unit I will live in once the contract closes  and do other minor work so and that work alone will be $20-$30K. 

I initially hoped to ask the seller for a credit to fix however I am hearing that the amt of credit you can ask the seller is limited by the closings costs amount (in my case max it will be $12K) so I am not sure what to do.

I am aware of the 203K option, but I am not sure I want to go that route as I am comfortable with my plans for down payment and monthly expenses currently.  Also, I would like the seller to pay for as much of this as possible as the house was NOT advertised (As-IS)

Any suggestions from seasoned homebuyers, or someone who has experience buying an older home?