From the two, I personally would probably go for the Vivace. I mean, both are nice, but you mentioned foldability, which is a little better, closer to the Mios', on the Vivace. Otherwise, they are similar, not that much suspension on any of them, but with comfy fabrics and nice seat units.
What is better, on the other hand, on Electa, is the larger, MUCH roomier bassinet, and also the seat space is a bit bigger. However, you are asking whether you do need a bassinet - if you're a first time parent, I would strongly recommend it, as it is much comfier with a newborn. However, if you want to save money and/or space, you don't have to go for one as both strollers have a lie-flat option, meaning you should only get a good soft/insert cot or a newborn-friendly footmuff (to give the little one more sense of comfort/protection from all sides). So, I personally would get a bassinet, but it is possible to go for a soft insert cot or better footmuff instead (and/or a reclinable car seat).
Lastly, I personally would go for the Mios more than those two. With it, I would NOT get a full bassinet, but the soft cot from Cybex, should be cheaper overall and perhaps fit under that 1k budget.