Hey there.
As for utilities you should prioritize: plenty of hackware, a piece of light armor, a medium storage unit, exp. utility shielding, and a structural scanner will serve you well. If you have enough spare support, medium armor could do. You don't need four power sources as backup on flight, as most builds will only really be able to handle 10 slots of inventory at this stage of the run, and other parts will fail before you run through that many engines.
A reliable way to get hacking suites is to kill operators with something with neutral or positive salvage, but be sure not to corrupt them, because hackware fries easily. The equation is in the manual if you want more details, but corrupting them to death will result in 90% of hackware frying. A typical rule of thumb for hackstacks is to have about 2-3 times as much hacking offense as you do hacking defense.
If you can find cooled or "Cld." flight units of any kind, those are great (except for Cld. Cesium-Ion thrusters, they have paper-thin integrity). They're capable of overloading, basically letting you get the heck outta dodge when you need to, for a small durability cost, and generate less heat. Cld. VTOL Modules can be hacked for at a level 2 terminal on -7, making them a great first cooled flight unit.
The main things I would say you want right now are hacking suites and a medium storage unit, the former of which you'll find from any operators, and the latter of which you'll find on any recycler from -6 and up.
The easiest way to get a flight build off the ground is to find your thrusters and hackware in Materials and transition at the entrance of Factory. Structural scanner can be great for finding hidden doors and quick digs between rooms. Once you learn to dig around the complex effectively, it's like a whole new world opens up. Digging a bit (1 tile melee, 3 tiles if dug at range) is a great way to move around undetected.
About your question regarding a second power slot: It depends on a number of factors. The main thing to think about is that unless you have a need for the extra power, then an additional engine is dead weight requiring extra flight units. Flight can often make great use of fusion compressors for boosts of energy when needed, and is fine running around at ~-0.6 energy per move.