Building My Own Beast - Questions and Bill of Materials

I was thinking about building my own printer for a while and what pushed me over the line was my Solidoodle 3rd Gen getting completely destroyed. White Lithium grease and ABS printed parts apparently don't mix. So I'm going to build one. But what got me on the idea originally was wanting a printer that could do what I wanted it to do and reliably, all while not costing all but one limb and a rib. So I'm putting just two of my extremities on the line to build myself a beast of a printer. My only printing experience is with my Solidoodle, making finer prints than the manufactureres could get and I've only printed in PLA. So I'm qualified right? ...
I have a basic bill of materials so far and I know I'm missing something(s), so I'm putting here in the hope that someone can tell me what I'm missing.
I also have some questions as to how some things work.

~NEMA 23 X+Y motors - Dual NEMA 17 Z motors, same for extruder(s)
~Megatronics V3 board - Polulu motor drivers - mechanical end stops
~Power supply
~8mm rails [First question! Would there be any benefit to larger rails? Stiffer, more accurate, smoother motion, etc? Looking at my SD3, the rails seem small for the speeds and accurate motion I am picturing. Maybe 12mm?]
~GT2 pulleys - GT2 belts - Ball bearings - Bearing platforms - Rail guides - couplers [Samish as rails question, would wider belts benefit at all? Don't back talk price, I'm looking at performance, I'll decide what price I pay]
~E3D V5 Hot-end - 2/3/6mm spare nozels
~Body and hothend mount: I have a contact for a local metal fabricator, I'll see if he can build me 1/4" Aluminum 6061 frame, solid bottom, table mountable, hotend mount and filament holder.
~Neodymium 1/4" magnets [X4 per] for removable extruders
~Wiring. No idea what all I need, but I know I'll need it. Specifics, if you know, would be much appreciated.
~I plan on using Repetier/Slic3r at least at first, maybe I'll decide to experiment with another software, but I feel much at home with this combo.
~Logo: This thing is going to be a beast and I want my name on it

My goal is 1'X1'X2' minimum build plate at at least 500mm/s perimeter PLA build rate and .025mm layer height. NO printed parts, almost all metal. Even the GT2 belt I am getting is steel reinforced to minimize rebound. 180N.cm holding torque motor. The good stuff.
So my main, most important question: What am I missing?

Update: After a bit more research I have found my goals to be of great limit. 100mm/s fast build? Apparently I am a child in a planet full of aged sea turtles. That's why I came here, I obviously don't know enough. Any tips and recommendations would be wonderful. I don't even know what it means to be part of a 3D printing community, I've just sat on the sidelines doing my own thing. I don't even know what questions to ask.

Edited 5 time(s). Last edit at 03/19/2014 11:23PM by MrDoctorDIV.

Hello!
Thanks a lot for the forum and all the valuable info :-)

I have built my own i3 Prusa Rep Rap and now I am planning to rebuilt it extruder to the one based on syringe. I have found several tutorials on blogs however all of them have Y axis built in a way that the syringe system can sit on it. Mine is slightly different and I am looking for a way or for a part that would enable me incorporating the syringe.

Is anybody there who can help?
Eventually anobody based in London who I could meet ?

Thanks

gomboszuz,

Unless someone who happens to know the answer to your question runs accross MrDoctorDIV's post, your probably not going to get an answer. I would suggest reposting your question directly to the forum rather than underneeth someone elses question.

MrDoctorDiv,

I have only built an Prusa i2, not something so big. However, I can tell you I have read this form plenty and it would seem that stretching the build envelope does indeed require sturdier parts. I think your idea to go up a rail size is a good one. I would also put a little more money on them and order some good hardened chrome plated ones. I am converting my i2 into an i3 and have taken this piece of advice.

Edited 1 time(s). Last edit at 03/26/2014 02:28PM by appdev007.

Sadly, I have already ordered my parts based on 8mm rails, including the rails themselves. Maybe that will be a future upgrade as I add heavier duty heads on my interchangable design [CNC, namely].