what power nema17 motors are best

Hi peeps, im new to 3d printing but have done loads of cnc upgrades to lathes and routers and im just gathering up all the parts before i build my first 3d printer, anyway i was going to use some spare nema23's 8wire dual shaft 3a per phase but having a further investigations into this new world ive found that they are way way overkill lol so i am now looking at the generally used nema17's, i will be running them on a Arduino mega 2560 with a ramps 1.4 shield at 12v though adapting to 24v is not a problem as i also have a few diy 24v15a power supplies lying around and i have found a supplier of nema17 steppers but he has different powers @ .65a .76a 1a, 1.3a, 1.67a, 2a which brings me to my query, what size amps per phase motor is best for a 3d printer with a 300x300x300 print area 1extruder to start with then eventualy a dual extruder, i have scoured the internet for this helpfull information but alas to no avail and all diy-ers seems to be using different sizes??? any and all feedback welcome

I like Oriental Motor's motor sizing tools at their web site. It allows you to calculate the torque required based on some data you input. You will probably have to guesstimate a few of the values, but it will get you close.

My printer has about the same build volume you're going for and I use NEMA-23 motors for X, Y, and Z axis, though the Y axis is probably the only one that really needs it due to its large moving mass. You can see the design by clicking the link in my sig, below.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

thanks dentist i will check that out n nice builds, my one is going to be similar-ish to your second pic i call the shape LT frame though i do have plans in mind for a cube with bed raising and from cnc tool changing an auto extruder changer for different colours but that will be down the line, i need to walk before i can run lol