There should be a Generations Arcee coming when Age of Extinction and it's merchandising train finally leaves the station. No one has seen pictures of it but nevertheless some of us are still looking forward to how it turns out.
You could try Animated Arcee.

But if you have your heart set on third party there are plenty of Arcee substitutes.

TRNS-01 Valkyrie by Impossible Toys. Good luck finding her. Impossible Toys ceased to be earlier this year and Valkyrie is much sought after.

MGT-01 Delicate Warrior by iGear. I think it looks better but I keep hearing of this toy falling to pieces.

PE-DX01 RC Motobot by Perfect Effect Taking it's design cues from someplace else, maybe IDW comics, this Arcee might not be what you're looking for but I found it fits in well with classics transformers.

There are probably others I'm forgetting.