*Depends on the bio-load. Do you want in-pond or remote filtering?
bioload would be like 2-3 koi and a few goldies (6-7), would prefer in pond cause it's going in basically the middle of the garden so i'd like it as seemless as possible will openly accept reccomendations for both
B) if it wanted to keep turtles in it?
*Triple it...

*A W/D with a good pre-filter.
really? triple? just for like 1-2 RES? ok nevermind that then...
C) didn't want it to freeze over in winter
*Insulate the pond and heat the water (install the filter remotely in a heated room (BB dies below 60*F)).
*Find out how deep the frost line is for your area and go
at least 18" below that.
what sort of insulation? like roll out fiberglass housing insulation? or like a sand bed? our pond got about 8'' of ice last winter.. is that the frost line? people generally say 3' depth is golden in our area...
D) keep the water clear (not clean... clear)
*W/D as a pre-filter then a pool cartridge filter to polish the water.
DIY? any reccomendations for a prefab? how much $?
E) predator proofing
*Put a greenhouse over it
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93358
Cage it with
http://www.afence.com/store/product.php?productid=25655&cat=440&page=1
use
http://www.afence.com/store/product.php?productid=25625&cat=439&page=1
for the top.
haven't looked over yet but will do. think all i need to worry about is raccons and the very occasional heron/egret
*Rent a backhoe! (half a day and it's fun)
believe me i want to but i dont think one can get through the fence to the garden 
*Use EPDM liner (45 or 60)
what widths do they come in? could i use one sheet? how would i join them if i needed to?
*Don't try to run pipe thru the liner.
??? i wasn't going to???
*Use a 4" sand bed under the underlayment (no warranty if you don't use it)
all around? ok
*Don't go cheap on the liner or pump.
*Realize that this is using a 1hp pump motor (not a pool pump) and how much this is going to cost running 24/7/365.
you lost me 
*Feed your labor and supply plenty of water (beer after the work is done or I can just about guarantee a leaky & lumpy pond

).
WILL DO!
*Rent a backhoe. (ya, I know I said it twice

).

*Get a digital camera and document it (video it too, you may win $10k!),
can do, who's going to give me $10K though? lol
*Don't show this to the 'folks' till the hole is dug

.
they said as long as i build it anything goes so let's hold them to it