Parts are available for that bike. Lots and lots of them. You will never have a problem finding parts.
That said, you will need them. Riding something vintage is going to require serious work, or being OK with riding it into a useless pile of **** fairly quickly. I probably spend an equal amount of time riding and working on my vintage bikes. Yes they can be "reliable", in the sense that they wont generally leave you stranded on the side of the road, but only if you maintain them. And even then you will get eventually get stranded, and if you cant work on it, it means spending a couple hundred to a couple thousand at a shop to get it serviced.
Compared to a modern computerized fuel injection bike that you can treat pretty much like a car. Change the oil every once in a while, and the coolant every few years, but otherwise just ride it. And you can get a modern fuel injected bike for less.
This isnt even to mention dropping it. If you drop that bike its value is now halved, everything will get scratched and dented and no one will pay you anywhere near what you paid based on that alone. You would have to pay someone a load of money to get it even back to the value you paid for it. Every time you look at it, you will have to feel like you destroyed something unique, which you did. If you have some ****** little fuel injected modern bike, no one will care if its got a few scratches when it comes time to sell it, and if you buy one with a few scratches on it, you wont even care at all when you add a few more.
Dont buy a very good condition vintage bike as your first bike unless you really really enjoy working on vehicles, and even then I'd say buy a trash one and fix it up over the winter, then ride it next year. Chances are you will either accidentally wreck it, which would be a shame, or it will not be as reliable as you'd like and you will spend more time getting it fixed and fretting about whether it will break down than you ever will riding it.
If you absolutely cant settle for anything that doesnt have a style like this, look into those chinese import bikes that are styled like old cruisers, for less than 4500 dollars you can have a brand new bike that is just as reliable as something built 50 years ago. I have one, and without a doubt I would recommend it wholeheartedly, hands down over any of my vintage bikes for a beginner. But I would also recommend a beginner get something like an early model cbr250 or a fuel injected ninja over either, simply because theyre more fun to learn on, more forgiving, and require way, way less maintenance which means more time for riding and less time for working or worrying. Even with 4 vintage bikes I daily drive my fz6r and have maybe taken my vintage bikes out 3 times this entire year. Spent a lot more time working on them and buying parts for them though.