Freddie Mac SBL (Top Markets)Loan Purpose: Permanent Financing (Refi & Acquisition)Loan Proceeds: $1,000,000 - $7,500,000Loan Sizing: 80% LTV; 1.20x DCRAmortization: 30 YearsLoan Term: 5 / 7 / 10 Years (Fixed); 10 / 20 Years (Hybrid ARM)Partial Term IO: Available @ 80% LTV; 1.20x DCRFull Term IO: Available @ 65% LTV; 1.35x DCRRate Types: Fixed & Hybrid ARMRate Lock: At Loan ApplicationNon-Recourse: Non-Recourse w/ "Bad Boy" CarveoutsPrepayment: Greater of YM / 1.00%Rate Buydowns: Up to 2.00% Assumable: Yes - Assumable LoanCash Out: Yes - Cash Out AvailableFANNIE MAE SMALL LOANSLoan Purpose: Permanent Financing (Refi & Acquisition)Loan Proceeds: $1,000,000 - $9,000,000Loan Sizing: 80% LTV; 1.25x DCRAmortization: 30 YearsLoan Term: 5 / 7 / 10 / 12 / 15 / 30 YearsPartial Term IO: Available @ 80% LTV; 1.25x DCRFull Term IO: Available @ 65% LTV; 1.35x DCRRate Types: Fixed Rate Lock: At Loan CommitmentNon-Recourse: Non-Recourse w/ "Bad Boy" CarveoutsPrepayment: YM; 3 Mos. @ 1.0%; 3 Mos. @ ParRate Buydowns: Up to 2.00% Assumable: Yes - Assumable LoanCash Out: Yes - Cash Out Available

Your comps and any adjustments to them for size, condition and features should help you set your rent, at least until you have connections to local committees or housing authority contacts that could provide practice-based guidance (sounds like a great tip from @Arsen Atanasovski).

Leverage size is going to make a big difference here as well - rate between 10-12% is probably expected for first time flippers but other factors are key as well

There are also REIA groups in nearly all major metros.Conferences: The Biggerpockets conference and/or the Best Ever Conference are two good ones that will let you meet investors of all shapes and sizes, from syndicators to LPs to direct owners in nearly all asset classes, from SFRs to Airbnbs to apartments and retail, industrial, RV parks, etc.

Being that the size of this property pushes me into the “commercial” world, do requirements vary significantly (do commercial loans have the same seasoning requirements, etc)?

Now that I understand how to scale I’m stuck trying to find investors that trust me for the size of projects I’d like to do.

Size doesn't matter, it's the fact that  you are getting your first deal done! 

The median I got for the area was $483 p/sq ft which puts it at $355,488 based on the size which is 736 sq ft.

The size of risk is inversely proportional to how thorough you screen.  

Assuming these are legitimate offices, this seems like a good size organization.