Hi

The e3d hot end comes from the UK. Yet another part that is easier to source in Europe. The e3d lite will do a limited range of temperatures and thus a limited range of filaments. I would go with the e3d-V6 full up hot end before I went for the dual extruder. It is a fun option though ...

There are a lot of minor bits and pieces that go along with a 3d printer. A few examples:

Filament holders
Filament guides
Ramps Fans
Print fans
Wire covers
LED light mounts
Heated bed spacers
Spare extruder parts
New extruders

That list is simply an inventory of what is on the table in front of me. All were printed on the printer that will be using them. None of them are vital for operating the printer. Some are more useful than others. Other than the spare extruder parts none of them go into the main part of the structure of the printer. That's where metal frames and metal to metal joints help a *lot*.

If anything, the V-slot frame construction is more easily modified than most kits. The stuff is designed to be tied onto and into. Every piece has mount points all over the place. It's very neat stuff. The Core X-Y guys have a lot of fun with it.

Printing up stuff to "improve" a printer is one thing that falls under "hacking a printer". Customizing the firmware is another thing under that heading. Taking a printer from single extruder to dual or quad would be a more extreme form.

Bob