Yes, what do you have for linear drives? I'm really interested.
This isn't what you are looking for probably, but....
The linear rail system from inside most inkjet printers is removable from the printer as a complete assembly. This includes tensioning, stepper mount, rails (usually with cotter pin), belts, and the like. I have around 80 matching pairs pulled already. I'm about to start testing the motors to see if I can drive them with a RAMPS board. If I can, I feel VERY confident that a 3d printer can be built with a few pairs. I almost think you can get away with making inkjet cart adapters to put at the end of the X axis rails to attach to the Y axis rails.
I'll post some images of what I'm talking about later today when I get into the shop. I'm not as interested in selling those as I am getting them to other devs that might want to poke around with a few pairs.
I also run into linear rail bearings sometimes, though I haven't in a while. I'll take a look around and see if anything stands out. I also find EXCEPTIONAL linear rail systems inside some tape jukeboxes and large format plotters.
Personally, especially for building mills, I am a HUGE fan of the HBLB-34 design
http://www.buildyouridea.com/cnc/hblb/phase8/phase8.html for a DIY solution. I built a few of these back when I owned an aluminum foundry and was EXTREMELY pleased with the results. I know that wasn't what you asked for but I had a sudden urge to nerd out about DIY rail bearing systems.
Do you own or work for this company? Also, really cool. I'm definitely going to come here when I need something.
I do sales for them, though in this BTC experiment I'm pretty much on my own. I do shipping and handling of sales I make, personally. This is part of the reason that my orders take a week or so to get out the door, I test everything I sell myself personally. This means I am a semi-professional power cable hunter 80% of the time.
I'm also really really suprised that nobody has asked about any of the electrical equipment. There are new in box electrical sub panels, industrial breakers, 20 amp special grade receptacles, etc etc; I just kinda expected to get hit with more requests than I have. Not upset about it, just surprised.
Firefop : still mulling over my reply, I understand what you are saying and I agree tentatively. My largest concern is that I just cannot use BTC to cover any of my overhead, ESPECIALLY shipping. I'll sell you almost anything off that page for around 50-70% listed price in USD, and in a way I AM charging a premium for taking BTC. This may not be fair but, again, I'm terrified of BTC. I'd accept face value BTC at current price if I could get purchasers to pay USD for shipping, gladly. Still.... considering. Because I don't plan on 'cashing out' my BTC I'm somewhat insulated from market manipulations... except for the cash overhead in shipping costs.
... even if the price is manipulated by say +50% when someone buys from you... on a long enough time-line it will increase in value to the point where you can trade/sell it above the manipulated price.
...................maybe