You may be able to find a good deal on second hand Jesse cases. I almost bought a set from an inmate in the flea market, but went with the BMW Adventure cases instead. They stick out a lot farther than the Jesses, but it's nice having one key that does it all and keeping the ability to mount a camel tank if I want to. Besides, here in NH, I can't split lanes, so a little width isn't a deal breaker. If I lived in CA, Id definitely go with Jesses.
I loved the Jesses on my Strom. Rugged, badass, and cavernous. I could fit my 1-piece 'Stich in one case with room to spare, perfect for locking up your gear when you want to walk around.
They are a bit heavy, but most of the weight is pretty low.
I almost went with Happy Trail cases, too. They're less expensive, and everyone who has them raves about them. You could probably mount them to that rack you bought.
Or, you could get some Givi cases and mount them to the rack they belong on. I had a Givi 42L top case and it survived when I totaled my Strom. If it were a sidecase, it wouldn't have, but it took a good hit all the same and went bouncing down the highway at 70 mph, and it's still functional. Has a big scar, but, hey, so do I. And, the shape of the Givi allowed me to put my full-face helmet inside. They're not as rugged or badass as aluminum cases, but they are surprisingly rugged and very functional. You could vinyl wrap them in something cool looking to give them some style... like digi-cammo.