Pure sine is still a bit more expensve. but in my view worth it,
funny things happen to some devices on modified sinewave systems.
As to integrated or seperate, its a toss up, in my experience its usually the invertor that goes belly upfirst. Its usually cheaper to go with integrated and less
cables to run.
As to brands, well I suggest good quailty units as I have had my fill of
cheap invertors failing, Mastervolt,
Victron, Xantrek avoid the cheapy chineese no brand stuff.
dave