Transtubes aren't real tubes, and you won't get a 15w tube amp for that price. ...But the peavey is still a nice practice amp. On the older models, the sound was thin, and the distortion was like a can of bees, but with enough EQ tweaking it was definitely useable... I hear transtube tech has progressed for them since then so it's likely better.
And I don't think the amp will mind that your pedal is larger, if it's nearby, why not hook it up? just sayin', mostly as a reason to avoid spending more on "reverb + delay + flange + more cheap effects" but it seems you don't plan on going that route anyway, so no biggie
I haven't used those other two. I'm sure the roland is great if you want portability , but I would think that if it's just gonna sit, why shrink it down to a 5" speaker.