Don't like upright position so which bike should I choose?
It’s awesome that you’re getting back into riding again. MTB style bikes have gotten a lot more sit-uppy in the years since you last purchased a bike. Their geometry has gotten a lot more slack and the headsets a lot shorter and the wheels are bigger so you tend to sit “in” the bike rather than stretched over the top of the bike. 

This might be an occasion where you should talk to your local bike store to see if an MTB is still what you want or whether a gravel bike which is a modified road bike with fat tyres but still has drop handlebars, might suit you better. It really depends on the terrain you want to ride on. 

A good store might be able to recommend changes like a slightly longer headset to an off the rack bike to stretch you out a bit too. Also some brands tend to be longer in the frame than others.

Good luck with your search.