Yes, the EXI D213F's are what I"m using on all of my mini planes and I have used them on heli's with good success. Hobbypartz.com has them, not sure if they are in stock or not though. D113F is the exact same servo, just plastic gears as stated above.
I will say this, and I know you don't want to hear it. If you are going to spend any money on the heli, do it on the tail. Get a GOOD gyro and servo so you will not be fighting yourself later on. My suggestion is at least a GP790+DS520. You can find these on the forums pretty cheap from people that are going flybarless.
If you must though, you can find a knockoff servo that has a speed of at least .08 or faster for the tail. 9g or 26g servo should fit on the tail, unless it's a pro version, then you will need the 26g as the 520 is. The servo has to be digital for the gyro that I'm going to suggest but not highly recommended.
The knockoff gyro that you can use, and again, I don't really suggest it, is the
HobbyKing GA-250. That one is in stock at the moment. There is one in the UK warehouse, and you can find that one
HERE, but it's not in stock ATM.
That gyro is a MEMS gyro and will be much better than the HK401b or whatever it is that's a piezoelectric gyro. MEMS is MUCH better, and even though it's a knockoff of the Quark, it's still pretty good. I can't stand HK, but I still have to go by what I experienced with that gyro, and it was pretty stable. Still some drift though.
Hope this helps. And remember, the only stupid question is the one that is never asked. So ask anything that you have a question for. We will be here to answer it.