There are several strong paths depending on your goals, risk tolerance, and how involved you want to be.If your priority is maximum cash flow, some strategies to consider include small-to-mid-size multifamily properties in cash-flowing markets, short-term rentals in vacation or business-travel hubs, or even note investing and mobile home parks.

Price is not much more for the larger size because most of the cost is in the transport.

.: $1,266.43/mo (adds ~$320 T+I)Cash to close (incl. points/escrows): ~$39.5kWhy I’m looking at itDuplex in a rent-rising area; path to market rents looks plausible.Bring both units to marketExit flexibility: holds as C-class cash flow, or refi if rates ease.Rents (current vs. market)In-place: Unit 1 $1,100, Unit 2 $1,050 - $2,150/mo totalMarket used in pro forma: $1,200/unit - $2,400/mo totalRentometer trend (2BR/1BA, 1-mile): Avg ~$1,017 - $1,180 over 48-6 mo; median $1,000 - $1,395 (small recent sample).My near-term view: Avg $1,200–$1,250, median $1,400–$1,450 (if demand holds).How it pencils (high level)At current rents ($2,150):NOI: ≈ $15,006/yr | DSCR: ~1.32 | Cap: ~9.7%Cash flow: ≈ $89/mo - very thin cushion.At market ($2,400):CF and DSCR improveLender view:Uses $2,050 rent and $320 T+I - DSCR 1.62 on their calc.Payment line: P&I $946.43; PITIA ~$1,266.43.Fees: 2.5% origination + UW/doc + title + escrows push cash-to-close to ~$39.5kWhat could go wrong (quick flags)Execution risk: Thin cash flow at in-place rents; delays to $1,200/unit hurt.Sample size: Recent rent comps are sparse - higher volatility.Leverage & prepay: 5-yr prepay + 8.42% rate = limited exit flexibility near-term.Ops assumptions: Vacancy ~7%, PM ~9–10% - small misses swing DSCR.

There are options out there that can be flexible on deal size, especially if the asset has strong cash flow or upside. 

What's the average optimal layout and size for a duplex? 

Quote from @Caleb Brown: There are 2 trains of thoughts and ultimately there's not a 1 size fits all. 

This property has 2 units with separate entrance. unit A: 3-bed/ 1 full bath and unit B: 2-bed/ 1full bath built in 1969 with a lot size of 45*214.

I'd go to a local credit union for a loan of this size on a primary.

What is the sweet spot for home sizes?

Basic stuff I've restocked:shampoo, conditioner, soap, paper towels, toilet paper, 1 frying pan, 1 medium size pot, silverware, knife large wooden spoon, dishwashing detergent, laundry detergent, olive oil, salt, and pepper.Some pro tips: I always do this shopping at Costco and buy quality items at bulk and a bit cheaper.