Fitting a MTB to a leggy beginner?!

You guys all seem very knowledgeable and friendly, so I wonder if you can help...I am a 5-foot-6 slim young woman, I weigh about 59kg (hoping that'll go up once I get fit again - feeling rather weedy right now!!), and have a short torso even for a girl, which means my arms and legs are longer than your average female. I have had so much conflicting 'advice' from various forums and bike shops about what type/size/brand of bikes I should try, that I'm going back to basics and scrapping my 'short list' of bikes in my price range with good spec!

I would like a hardtail for 450-650 UK pounds, which I guess is up to $1000 or so. I don't want it to be too heavy, as I will probably do some road cycling on it too, and I ideally want the spec to be good enough to give me the confidence and motivation to do proper cycling and learn to get reasonable at it.

So my question is...
Am I actually a 'typical' female body shape, in which case would any particular men's bikes be worth trying?
Seeing as everyone keeps telling me different things about whether a bike fits me or not, can you advise on how you actually tell if it fits??!!

Longer legs shorter torso is the body type that is behind Women Specific design, so you may actually get a better fit trying WSD first.

A good mtb fit - torso at a 45-ish angle, arms extended but relaxed; head/neck comfortable without straining; saddle up so that leg is extended but not locked ( this is your climbing position, it will vary for the kind of trails you ride on)

You don't want to feel any tension in neck and shoulders, no low back pain, no cramping. Pay close attention to how your shoulders feel.

If you are coming over to MTB from road riding, a correct mountain bike fit will feel shorter in the cockpit than you are used to.

I'd get recommendations on what local shops are good at fitting. If your arms are disproportionate, your fit may require some extra tweaking.

You can ride mountain bikes on the road, certainly. But they are slower due to gearing, and if you keep knobby tires on them, the ride is not as smooth as a road bike.