The main downside of converting your bike into a touring bike is the front suspension. You probably won't be able to add a rack to carry a second pair of panniers on the fork, so you'll be limited in how much you can carry. Replacing the suspension with a rigid fork is possible, but might be a bit expensive, and it might mess up the geometry of your bike, since it was designed for a suspension. Then again, ask around - your LBS might be able to obtain generic chromoly forks for $20-25 if you're lucky.
If I wanted to use that bike for touring, I'd add a rear rack, a pair of full fenders, a front basket (like a Wald 933) or a handlebar bag, and a pair of good lights rear and front. A big spendy item is of course the panniers.
I'm not a fan of flat handlebars, and the cost of a drop-bar conversion is quite high ($150-200) - I'd suggest trekking bars, which are inexpensive ($20-25) and compatible with your existing shifters and brake levers.
I find them quite comfortable for long distances. You might need a new stem with a 25.4mm clamp area if your current handlebars have an oversize 31.8mm clamp area. You'll also need some handlebar tape to wrap the trekking bars with.
I myself did such a touring conversion on my hybrid, which used to look like this:
It served me well on tour once modified with a rigid fork
Or, here it is with another stem and no touring load, on the morning I rode back home 252km in 12 hours. The angle of the handlebars is a bit radical on that picture, I tilted it backwards (more level) a few km into the ride.
The conversion was somewhat expensive, very labor intensive, and in the end the rear wheel was too weak for reliable touring with such a high load. I had to repair many spokes.
But I still toured thousands of kms with a heavy load, on a converted hybrid. My main gripe is that the LBS didn't bother to fit me on the bike, and sold me a model that was too small. Their lack of professionalism bothers me to this day. The stock seatpost wasn't even tall enough to let me reach a proper leg extension while riding.
My advice would be to make sure that the bike fits you well enough that you can get comfortable on it for long periods. Go on a few long rides before considering converting the bike for touring.