I wouldn't personally buy a Hughes and Kettner amp unless it was one of their tube amps... They make high end tube amps but I've never been impressed with one of their solid state amps. It kind of depends on what kind of Marshall cabinet you have as well... It will dictate what wattage you can run through it and also what kind of sound the speakers are capable of putting out... Most people overlook speakers... Speakers and the type of cab also dictate what your sound is like... It doesn't matter if you have a H&K Triamp or a cheap low end solid state head... If the speakers are lousy, your sound is going to be lousy...

Now, I'm not sure what you budget is but if you're looking at a JSX I would suggest a Marshall JCM 800/900/2000 TSL over the JSX... especially if you're running a Marshall cab... The JCM's are very versatile... although not as verstile as the JSX... I think they get a little bit more crunch... Even though Peavey amps are killer amps... Especially the Triple X and the JSX... Check out the JCM's... they're a super solid tube amp that is pretty much industry standard these days... They can nail most any tone out there if you have a basic set of pedals or a multi effects processor... which is another alternative as well...

If you have a multi effects processor like Line 6 Pod or PodXT Live... or Boss Gt-6 or GT-8... you can always spring for a power amp and use the preamp of the multieffects processor.... You can purchase a Mesa Boogie Triple Rectifier Power Amp for between 800 and 1200 dollars.. depending on where you're buying it and whether or not it's used... This kind of set-up is good for studio type stuff... and it's not bad for being on the road either... you get the best of both worlds... you get solid Mesa Boogie tube tone... but you also have the versatility to use the amp models on your multieffects processor.... Just a few other avenues to look into I guess...

But I personlly would take a Peavey tube amp over a H&K solid state amp any day of the week.