My $.02
Honestly, I wouldn't rush into buying even a 6R as a first bike, especially if you need a loan to buy one.
To give you a better idea, I can tell my story.
Before I took the MSF class I was even doubting if I was going to get a bike (not the best means of transportation in Seattle, rains too often). Loved the MSF class and the feeling of riding a bike. I was pretty low on cash then and didn't have too many options, but wanted something more than just 250cc.
I got a 1976 Honda CB550 in great shape for about $2k. Carburated inline 4 that redlined at about 9k, 5 gears. The bike was capable of highway speeds, topping out at about 90mph - plenty for a new rider. It handled great. I loved the vintage look.
On the downside, the old Honda eventually needed some work done to it. The previous owner did a great job tuning the engine, but didn't know much about electrical. 2 months after buying the bike, the charging system broke. I had to diagnose the problem (burnt rectifier), replace the part, and along the way checked and cleaned all connections in the charging circuit. Even though it sounds like a giant PITA, I learned a ton about how bikes work in process.
While still riding the Honda, I knew that I wasn't going to keep the bike forever, so I was saving for something more modern. Already knowing what I like from some riding experience, I started thinking about what bike to get. I read a bunch of forums, review articles, and narrowed it down to 2 bikes - FZ6R and Ninja 650R. After test-riding both at different dealerships, I liked the FZ6R more.
I wasn't ready to buy a brand new bike, so I waited for a good deal on CL. Soon enough I bought a 2009 Raven FZ6R with less than 1600 miles for $5k, sold the Honda for the same money I bought it.
This bike has probably three times the power of the old Honda, it's loads of fun, but is still comfortable enough to do long trips. This is all I wanted from a motorcycle. I'm sure I will still upgrade to a different bike at some point, but there is no rush.
Basically, my advice is to get something cheap. Something that will give you a starting point in a riding career, but won't be too expensive to fix if you drop it. The first bike doesn't have to be the perfect fit - the point of it is for you to learn what you like and what you don't like in bikes. Then there's always an option to upgrade. You're only 20, you have so many years of riding ahead. There is no rush.
Another thought - put aside some money for riding gear. Get a good helmet, a jacket, gloves, riding boots. Get some riding pants for longer rides. (I commute in jeans but wear leather pants on longer trips).
Also, IMO it's not worth it buying a bike from a dealership. Like someone said here, the going price for a used FZ6R is 4-5k. Bring your buddy with you to take a look at the bike to make sure everything is ok. Also, you can search for threads here describing what to look for in a used FZ6R.