I'm looking for a mountain bike with speed and a good Uphill climb system.
The 'speed and good uphill climb system' is your legs . Seriously though, try asking at off.road.cc .
Any decent MTB will have low enough gears to grind up a hill. So long as you don't buy one because you want low gears for road use, or you could become one of the people who labour along the flat (fat tyres and smaller wheels) getting overtaken by road bikes. These days, I give a gravel bike a look if the off-road riding isn't too gnarly or technical.
Why is good Mountain bikes?
Whyte are good mountain bikes
This one has bad Uphill climb system.
It's no good asking here Nichola, I don't think the majority know what bikes are, let alone mountain bikes.
A bit more info about what you're looking for might help, including budget.
Personally, for a fast mountain bike I'd suggest a short travel hard tail ( my personal bike is an Orbea Alma Team), or a double suspension (I'd be looking at the Scott Spark).
Hard tail MTB are quicker than full suspension bikes until it becomes very bumpy then Full suspension is a must. A full lockout like Scott. something like this
Probably best to ask here