Hi and welcome.
For what the Max offers, it's an incredibly affordable printer - it's what attracted me to it in the first place. If you go ahead with the purachase I don't think you'll be disappointed
It's also able to be run incredibly fast.
Bear in mind that there's the assembly - are you comfortable with that? Some find the process enjoyable (like me) but some may find it frustrating. If you like Lego, you'll love it.
As far as the e3d goes - yes it's a great hot-end, a lot of us here are using it on our machines and the process to install on the Rostock is simple. I'm using this mounting bracket designed by one of our forum members named 626pilot:
http://www.thingiverse.com/thing:137140 just print it out with the stock hot-end and you're good to go!
A good addon to this mounting system is this fan shroud:
http://www.thingiverse.com/thing:257188 - it locks nicely to the e3d neck and doesn't let the fan vibrate (which is annoying). Again one of the forum members, Cope413 put this together
Now on to dual extrusion. I have not modded mine for dual (yet), but quite a few others have and there are some decent threads which discuss this somewhere.... Now where are they?
Anyway, here's the dual e3d mount that another fine forum member, Bubbasnow put together:
http://www.thingiverse.com/thing:278076
A company named Trick Laser:
http://tricklaser.com/ makes some magnetic ball arms for the Rostock and again some users here have swapped them out and been quite happy. I recommend just using it with the stock arms for a while - I honestly am pretty impressed with the stock accuracy and haven't felt the need to swap to anything else. I would like the ability to swap out the hot end easily though, and having magnetic arms would allow that easily.
In the end, I'm really stoked with my machine and I think you'll like yours if you go for it
Good luck!
