Yeah, I think I'll wait to see the in-hand pics of the HT Vader before I go down that road. It's the reason I made my $25 Vader - to have in the background until I can get a better understanding of what HT will deliver. The HT proto looks "just okay" at this point, but it's possible it could be tweaked and be great. It's like HT Ben - do you spend $400+ to customize the SSC Ben, or wait to see what the HT final product looks like?
I'm hoping Eczamurai will sell casts of his amazing Vader facemask. Once you have the the mask right, the rest isn't hugely hard. Matrix's key assets are the Kaiyodo mask and the SSC ANH suit. They are both incredibly accurate.
Not the ones you need, at least easily. Yeah, you can buy the ROTJ DX chest box for $100 and the dome (w/mask) for another $50+ but where's that going to get you? $600 instead of $500? Then... what if you get 8 of the 12 items and can't get the other four? You can get gloves, boots etc. pretty easily but it's somewhat rare to see things like the ANH jumpsuit.