Howdy EZ, welcome,
Drag bars,...Yep, I did that too....
You want 1" bars, 28" or longer, any shorter will make for heavy steering.  4" risers so the bars will clear the tank.  If you want them lower, you need straight bars, they can be a bit of a strain on your wrists on longer rides.
Try E-bay,..Bars should be $25.00 or $30.00...Risers, $30.00 +...
If you're on a budget, and like rigging stuff, you can fashion your own risers from a pair of deep well 19mm sockets or bmx bicycle footpegs ($10.00), then but longer bolts to fit and presto.  I did the bmx ones on mine...
Two riding tips,..Use the front brake, it does most of the stopping,..
Learn to countersteer,that's pushing he handlebar to steer instead of leaning...
Here's a pic,...good luck
Serowbot

Here is a pic of the factory setup on my '86.Like Verslagen said go with a 30" bar.Since you already have buckhorns your cables will be long enough to go with a wider bar.Stock bars are 28"(I think).All I see in my mirrors are my arms.

Here are a couple of styles to kick around for a custom  look.Also check out Sluggo's,and Strangeling67's bikes.There are others on here too with customs,just can't think who right off.There are also a couple of guys that went bagger style too.