Can I use a combination of two mobile air conditioner units to cool house?
In terms of just "can two mobile A/Cs cool a 1000 sqft area", yes, they certainly can. I lived in a similar-sized apartment for a couple years and did just that -- one unit, a monster mobile A/C, was in the living room and cooled the living room, dining room, office, and kitchen; the other was in our bedroom and cooled just the bedroom.

However, you mentioned that you have three bedrooms -- if those are occupied, I assume the occupants will want to close their doors at night. At which point, the cool air won't be able to get into the bedrooms.

I would carefully consider if the investment you'll have to make into the mobile A/Cs is worth the trade-offs (especially the noise, as Jeffrey commented), considering that you'll eventually want to fix the central air anyway.