What? Clowns only use anemones to host in. Clowns will only host in bubble tip, sebae, long tentacle, and carpet. They will NEVER host in a condylactis. Captive bred clowns will host in ANYTHING *that means live rock* This is because they are not from the wild and have NEVER seen an anemone. A 10g tank is way to small for an anemone.
You can have 2 clowns in a 10g tank, but 12-14 would be better. You MUST get both clowns at the same time or the clown in the tank originally will kill the new clown. When the clowns mature one will become the male and the other will become the female. The female becomes larger. If you have a pair one will become the male and the other a female.
You will need to buy roughly 6 pounds of live rock. Every gallon you want roughly a pound of live rock. *Adding lbs of rock will cause less water to be in the tank* Since you are doing a FOWLR *fish only with live rock* you can use regular fluorescent lighting. Also get a bag of live sand. You will not need a sump for this size tank, using a regular HOB filter will work great, also mentioned a protein skimmer will help dramatically.
Mentioned before you will need a hydrometer to measure the salinity, salt, spare 5 gallon bucket, and an extra heater. You will need to heat up your water before adding it to your tank since it's going directly in. I recommend only using RO water if you can get it from a local shop, won't be expensive at all to do a small water change *usually around .75 cents a gallon*
You will have an algae bloom when your tank is first cycling. Getting small snails will help with algae. Do not get turbo snails for a 10g since they are pretty large.
You could also add some small inverts if you wanted like a cleaner shrimp or feather duster.
Enjoy your tank