It's impossible to know if either a haddoni or gigantea will need to be treated prior to receiving it. Generally speaking, haddoni fare much better than gigantea, and many don't need any type of treatment. Since you don't have any other anemones that could be infected in your tank, you can add it directly to your tank.
If you're looking for a gigantea, I recommend having a QT tank and Cipro on hand. If space is an issue, you'll need to try to make space -- a 10 gallon tank doesn't take up a lot of space! And if cost is an issue, then consider it part of the cost of owning a gigantea.
However, based on your location, your best bet is to contact Your Reef in Roseville. I'm not sure if they still do it, but they had someone who was QTing carpets offsite. The nems weren't cheap, but at least you know that they were properly QTed.
All that said, the cost of ordering a gigantea from Blue Zoo and purchasing a QT system with Cipro is still going to be cheaper than picking up a QTed gig from Your Reef (based on quoted prices the last time I inquired).
