Welcome to gliding. You won't regret it.
At your age, you're 'here' at the right time. You can go solo soon as you're ready, not too old dog to take longer to learn new tricks.
While winch may be statistically bit more dangerous than aerotow, you get trained to proficiency to make sure nothing happens, and if it does, you know what to do, ie later on in your training, you'll practice simulated cable breaks. It's a sign that after maybe 10-15 of those, you may be sent solo, if you do mainly/only winch launch training.
Winching is definitely cheaper for initial training. I did it the other way round due to no winch options at my previous clubs, only started winch training after going solo off aerotow. Once you get the basics of winch and get over the initial acceleration that can confuse your senses (scare you, maybe), you learn how to do everything by the book.
Not sure where you'll be flying, but depending on site, simulated cable breaks may be more demanding. If you have big, long side with not many trees at the edge, it would be less stressing ;-)
As others said, the angle feels much more due to acceleration (inner ear liquid pressing to the back, making you feel like head/body tilting up more than in reality), but after transition to full climb, it is then due to looking directly to sky ahead, although you should be checking the wingtip etc. Above 40ish degrees is excessive and produces too much drag. It also depends on the weight of glider, K13 being common, could be more than, say K21 or Twin Astir, as well as any headwind component.
You want to be practising launches and circuits/landings, so aerotows are costly per launch and if you know the handling basics, sitting on top of ridge or thermalling is nice, but doesn't help with circuits much. Also, depending on club, you may not be able to do more launches per day, if aerotowing, while clubs tend to do more launches by winch, another big plus, if club operates weekends only and not every weekend is good enough for circuits, not even talking about solid thermals..
Winching is thrilling/scary at first, even for me, being used to aerotows, but you'll go solo faster and converting to aerotow solo once you're good on winch, is easy peasy. the other way round, not so :-/
As said, your hands may want to grab on something initial flights, so the hand you're not using, put it on chest, hold strap. I had such times on bumpy, more demanding aerotows, or when the tuggie did steeper/faster turns than I'd have liked. Later on you'll have to use left hand, but that's later on.
I don't want to sound too off-putting.
You'll have a blast and you'll know straight away if you're glider pilot for the rest of your life. Even if you fly power later on.
In case you don't have it yet, grab a Piggott's or Ken Stewart's book or two, second hand off amazon. I find Piggott's Beginning Gliding too waffly in some aspects, talking bit too much about feelings of pilot if they don't improve well, etc etc. Not that it's bad, but..
At your age, also check
http://www.airleague.co.uk and their scholarships. The deadline is late February. Others may mention other scholarships for youngsters getting into gliding. Hope we'll see you in the club news and first solos' pics in S&G mag this autumn/winter.