1) it will be extrememly hard using only the 14pce
2) gearbox restorers are very reasonable price wise, just take the box out yourself to save a lot of money, just take the gear box, not the extension housing or the bellhousing
3) couple of days for a mate of mine to get his EA auto box, i think its less for manual boxes, but to be safe i'll say a week - week and a half tops
4) i'm pretty sure someone sells kits, i've heard about them alot, but have never actually seen one in the flesh (so to speak) i got al my gearbox rebuild bits from a parts place (not that hard when you've got a popular box like the W50, but i'd say the W57 would be just as easy to get parts for