Alex, you should wear a suit. You can never overdress for a job interview (heck, I even got all dressed up for a job at a sandwich shop. The boss commented that I was the only person under age 20 to get that dressed up, hired me on the spot and made me a supervisor within a month. Dressing up seemed to work out for me there). If you're going to present as male eventually, I'd just wear a male suit
as long as it fits properly. I just recently saw a pre-T FTM (or maybe she was just a butch lesbian? I have no idea) wearing a suit and it looked awful because the shirt was way too big around the neck and the shoulders were obviously not wide enough for the jacket.
If you're worried about discrimination, you can wear a female style suit and shirt but put in a skinny tie with it. You'll get the female presentation but also a touch of classy gender non-conformity.

I always loved the look, reminds me of the suffragette movement.
I get my suits from this store called Express (not sure if you have it in the UK) because they carry pretty affordable suits in small sizes (I know we're about the same size, and it's such a PITA to get small sizes in suits here in the US). This is what I basically wear to work (just I would never wear the scrunchy sleeved jacket):

You can easily masculinize this wearing a shirt that buttons up to your neck, and putting in the skinny tie. If you want a more manly look for the jacket, get a jacket that's a bit longer than the one in the photo. Or, you can also try on some sports coats in the boy's section just as long as it's the exact same shade of black/charcoal (or grey or navy) and same material as the pants.
And... for formal job interviews, don't wear anything that's brown. Seriously, I love brown suits, but they're (sadly) not very accepted for formal wear (unless you're Ronald Reagan). It's starting to change, and brown is perfectly fine for more casual office work
after you get hired.
You might have some more leeway in dress since you're still a student, but you should def go all out in formal attire. And, if it turns out to be a bit more casual, you can always take the tie off, unbutton the top button, and casually throw the jacket over your shoulder.