If you are using conventional loan or maybe some other loan product, then they will do their own bank appraisal and you may have to pay more or less than that down payment, so check with your loan officer too to make sure what you are bidding will work for them and your cash reserves or cash to close are appropriate.If you are paying cash then it doesnt matter.I think you can only bid low if you think the property is worth less, or you are the only bidder.   

I may want to purchase the SFR or multifamily I live in with a Conventional 97 or a FHA mortgage.

If not, you might just consider going 5% conventional financing and leave the equity in your current house and get a lot more cash flow monthly.

Rental comps and EMI numbers post conventional loan refinance, indicate $200-$300 cash flow. 

My suggestion is to you use a private lender or non-bank commercial lender, they will have more flexibility than traditional or conventional sources. 

I wonder if I can get a conventional loan under our new established LLC. 

Is it similar to a conventional loan where you have to put a down payment or can you do zero down if the seller agrees?

We also, recently purchased our first investment property (conventional 20% down) as well.

If you give them equity, you also give them risk and those that are investing in me would prefer to be segregated from that.If you're doing conventional cash out-refi's and are able to put their money to work for them twice per year (timing things perfectly) that's really a 12% annual return for them.

Thinking about this, with 10 conventional loans, you have the potential to buy $10 million properties.