You want to get a soil that has micchorizae (sp?) and pearlite and a good loam. The cheapest potting soil is usually just compost and dirt. The Michorizae are some kind of fungus that attach to the roots and promote growth throughout the plants life. I usually try to make a 3' by 3' hole when I can afford the soil. I also buy a special supplement that adds the good stuff to the existing soil. Some folks make a 5' deep by 5' diameter hole but that takes a lot of dirt to fill and may not be of value in your area since you will be looking for a variety with a short maturing season. A much smaller hole will work if needed but the roots will not grow as much and the plants will not get as large.

A female or feminized seed should result in a guaranteed female plant. Normally seeds are a 50/50 male female ratio. However check for a reliable seed bank since some folks on this forum have had problems. Some "female" seeds turn out not to be so.