Great question Lon. Here is some information that you may find useful:
Type I is a general purpose portland cement suitable for most uses.
Type II is used for structures in water or soil containing moderate amounts of sulfate, or when heat build-up is a concern.
Type III cement provides high strength at an early state, usually in a week or less.
Type IV moderates heat generated by hydration that is used for massive concrete structures such as dams.
Type V cement resists chemical attack by soil and water high in sulfates.
You can usually also find blended portland cement like "Type S" at home depot and also various hydraulic cements like "white cement" which are used for waterproofing applications like the plaster coat for a swimming pool.
The terminology changes depending on your geaographic location which is where the confusion comes in. What you refer to as type 1 is in fact the same as type 10 available locally in Vancouver BC, Canada. This type 1 cement that you have in your local home depot is the one that you are most likely looking for.
And to answer your specific question - yes you can use the portland cement available from Home depot. In fact this is likely the cheapest cement you will find available anywhere. The bulk purchasing power of home depot is so strong that they are able to sell bags of cement at a lower cost than you can receive direct from a concrete products supplier. The ONLY disadvantage of the Home depot cement (as with most cement suppliers) is that the bags are very difficult to accomodate. Locally the only ones available are 40Kg (approximately 100 pounds).
Again, great question. I hope some of this information is helpful!
Cheers.
Steve Goodale www.ArtificialRock.ca 1-888-267-0802