bkvlad:
In my opinion, the pot size depends on the size of the plants root ball. You can pot it in a smaller pot and in a year or so move up a size to a larger container. I'd never put a small plant in an overly large container because the soil would tend to hold water longer which you wouldn't want water standing around tender roots but I also think a small plant looks a bit out of scale in a pot that is too large. You want the plant to be the attraction first and not the pot.
As to the potting medium: Most big box stores (Lowes, Home Depot, Wal-Mart) carry a bagged cactus and succulent soil but I'd still add more grit for better drainage because I've always found most bagged soils to be water retentive and too heavy. I grow most everything in a mixture of potting soil and orchid bark mix which really helps with drainage. I used to add perlite to the mix as well but found I didn't need it because the orchid bark is a combination of perlite, wood chips and charcoal and it drains very well. Just remember, if you do go with a gritty mix that drains quickly, depending on the location of the plant you might have to water more often. If it's outdoors and gets rain on a regular basis it won't need supplemental watering but if it's kept inside year round I'd say a once a week soaking would be more than sufficient for a jade that's planted in a well-draining mix. If it's regular potting soil, once a week watering is too much and will probably cause root rot.
As to the potting medium ad on e-bay: Al (Tapla) is an expert Bonsai grower and very knowledgeable about plants and soils; his potting medium is top notch. I used to read his posts on a forum I belonged to a few years ago and I did purchase a bag of his mix and I highly recommend and vouch for it, especially for cacti and succulents! I just had so many plants that it was cost prohibitive for me to continue to purchase it so I used what I ordered and when I ran out I went back to mixing my own using the potting soil and orchid bark mix.
