Too much on your plate? That entirely depends on how keen you are, and how willing you are to look after it. We cant really make a decision for you, you have to do that.
We can only give you advice on the how to successfully enjoy/keep your reefs/marine!
Just to start off, the fish you mentioned are nice fish, I can see why they caught your eye!
The Blackcap Basslet, Royal Gramma, and Jewel Damsel will be cramped in a 10g. The Achilles is out too im afraid, but not entirely out of the equation! Because you havnt started yet, it will benefit you.
Id go to a few websites like liveaquaria.com and look at the fish you like. Not all fish are compatable, but we can help you there.
Just get an idea as to how many gallons they need etc. The choices for fish in a 10g isnt that great im afraid!
As Lyle said, the extra work isnt all that much more, and IMO the benefits are that far greater. Once you go marine, not many go back!
I think Lyle makes cycling a marine tank a little bit of a chore, but its not. If you buy Live rock, which is highly recomended, that basically cycles your tank for you, it harbours beneficial bacteria, so when you place it in your tank, its like introducing large quantites of good bacteria. You do have to wait for whats called "die-off", which are organisms that didnt make the trip. The pollute water, and you basically have to wait out the pollution caused.
To see if you want to go marine, pinned topics at the top of each forum can help give you a gist of what its like, and so can many interesting journals, found in the Nano section, and theirs a pinned topics about individuals tanks here at TFF.