Those 2212 sized motors are all going to be for small quads and small props, it’s not going to work well for carrying around any weight, or reliability.
I wouldnt advise going 6 cell unless you really REALLY need to, for example if you’ve got low KV motors, lower than say 700KV. Sometimes motors, ESCs and other electronics can be more expensive for 6 cell, and the 6 cell battery has some extra weight overheads built in too. Every gram counts!
450mm frame is a bit limiting due to max prop size being about 11inches - but you can still do pretty good with that!
Probably my ideal setup, assuming reliability to avoid camera loss, for this size frame would be:
- Turnigy Graphene 4 cell 5000mAh - not too heavy, not so small you dont get any flight time
- T-Motor U3-700 - reliable, efficient
- T-Motor 11 inch carbon fibre props
- Hobbywing X-Rotor 40A - or any reliable high quality ESC
According to some rough calcs you’d get about 15mins flight time and well over a 2:1 thrust to weight ratio - before adding the payload.
Honestly though, there’s a million motors and props out there - almost too much choice. It comes down to a balance of requirements/budget/availability.
Availability can be a big issue actually - calculating the perfect combination and actually finding where to buy the components can be two very different things.
I’d advise pay the tiny amount for an eCalc subscription and spend about a week or so messing around in there - the subscription cost is tiny and nothing like the saving on buying the right motor compared to buying the wrong motor.