I was just list listening to your links again. Does the Marshall provide the clean tones you need? It's difficult to get a high gain amp to sound clean by rolling off guitar volume, or switching to the "Clean" channel. It's just the way the amp is built. It will never really happen. If many of your songs, or the band's overall sound depends on a clean guitar sound, then throw as much filth as possible for choruses and bridges, then I'd be looking for the best clean sound I could get. Adding filth can be done with any pedal combo or even rack stuff later. I'm more in the stoner/psych camp, so I'm usually looking at different amp sounds, but it doesn't matter the genre when looking for a good clean tone to build off of. I'd start with the Marshall if it has the cleans your looking for. The Engl is also an awesome suggestion. I've heard some amazing Engls over the years. Blackstar is also a good option, as well as Orange. Since I'm more in the vintage camp, I'll throw Marshall JMP and Hiwatt into the mix, but if you do any touring, you probably don't want to be hauling old amps around because of reliablity issues.