In an answer to a question posted online, you referred to
|Monrovia is a wholesale-only nursery and does not sell retail or by catalog. Monrovia products are carried by independent retailers nationwide. You would need to check directly with the retailers in your area and see what they have as they each carry their own selection of plants and some may carry products in addition to Monrovia's.|
In any case I would suggest you work with your local retailers to see which junipers they have in stock (or expect to have in the spring) that you could use for the purpose you have in mind. "Spearmint" is just one named cultivar of Juniperus chinensis. There are hundreds of different junipers on the market and many could be used as substitutes for that one.
Here is some detailed information on Spearmint so you can see roughly what it is like as a basis for comparison.
I hope this helps.