Regarding the finished floor surface, you say 'engineered wood flooring'.
If by this you mean a length of 'real wood veneer' with blocks/strips underneath to give it rigidity I would advise you to avoid it like the plague!
I paid over £30 per metre for this stuff, was told I could sand it and re-stain when it needed it and that it would take hard knocks like children running/playing on it etc.
Fitted it strictly according to the instructions and really took my time to make a professional job of it. Got lots of favourable comments from floor layers/carpet fitters etc and was very pleased with it.
Then my granddaughter knocked over a glass of plain water which was little more than a quarter of an inch full. Went into the kitchen to get a mop and 30 seconds later walked back in to find 4 lengths had lifted along the edge. These boards were tongue and grooved with interlocking ridges on the tongue and also glued with the glue supplied from the manufacturer.
The shop I bought it from, (a local DIY shop with emphasis on DIY), sent their salesman/surveyor round to have a look. His opinion was whilst it had been laid correctly it was not a job for a DIY enthusiast and as such he would not recommend a refund. Got an independent flooring specialist in to have a look and he said the boards were not constructed to withstand every day living in a family home. In his opinion these type of 'engineered' boards were nothing more than a piece of veneer with some random backing strips glued on and he wouldn't use them in a childs play house, never mind a normal family home. It took over 3 months, the threat of legal action and then a report from the independent surveyor on headed note paper before they gave me a full refund.
Either, use real wood which has been seasoned and treated to be used as flooring or go for a good quality laminate floor. With the laminate type ask for a test sample. Take it home and immerse it in a bowl of hot water for 30 mins. Take it out and let it dry on top of a radiator over night, if it is still in good shape the following morning go ahead and buy it. If not move on to the next one that takes your fancy. I did this, paid £16.99 per metre and its still down and looking good about 9 years later.
Really?