FYI: My understanding from my research into this machine (I own one) is that the Brewtus does have a rotary pump for their plumbed in version. That version is apparently only readily available in Australia and in Europe. A kit has to be requested from Whole Latte Love for machines in North America if you want that option.
Yep, the plumbed-in version is available in Australia. I'm sure that even if a kit weren't available your friendly neighbourhood technician would be able to rig something up for a few hundred bucks. You will lose the ability to use the tank, though.
nB: If we're going to get technical, the brewtus doesn't have an e61 group, it has an eb61 group. I have no idea what the difference is, but I thought I'd point it out for completeness.
No, it doesn't, but I assumed your goal was the best possible espresso since you cite the La Marzocco GS3 as your ultimate choice, if price were not an issue.
I think that that's a fantastic point to make. There is absolutely no substitute for hands-on experience. It would be well and truly worth your while to actually try out some of the machines in your price range if possible, and to relate your specifications back to what you want in the cup. For example, I think that the GS3 is pretty phenomenal when it comes to magnifying the more subtle and fleeting flavours that you get in a great espresso blend, but if what you really want is to get a rich and chocolately espresso at the expense of these flavours, you probably don't need to cough up the dough for a GS3. Specifications are all well and good, but there's more than one way to skin a cat.
FWIW, I'll throw
this into the ring as another machine that you might like, but that doesn't meet your specs. I haven't used it, but I thought that a few of the other machines by the same manufacturer were quite good.
Cheers,
Luca