It is the ARR without the engine ($189 from A-main!). I used my old B01 engine from my GS Storm RTR.

Throttle servo: Z590M. It lasted a few gallons with my storm, and about a gallon on my old XXX-NT as the steering servo, and it seems to do the job just fine.

Steering servo: Futaba S3305. The one with ~125 oz-in of torque and .20 transit time. I "splurged" a whopping $33 on it. It is obviously not the best out there, but it is MUCH better than the z590 I had in my Storm. Im sure this also plays a part in the handling of this buggy over the storm. If I get into racing enough that I am really competitive, Ill upgrade. However, Ive always been able to do pretty well with less, so I might just leave it like it is unless I really feel it will make a difference. My problem has always been more with the DNFs than with just getting plain beat.

Transmitter / Receiver. I am using a JR XR3i. The receiver is the JR RS300, the one that can change frequencies, but the transmitter requires crystals. If I find myself always having frequency conflicts, Ill probably try to find a used XS3i from ebay for the synthesised frequencies, unless there is a cheaper synthesized radio out, or a better one for the same price. I only say the XS3 because it was popular the last time I was into RC, but I am still a newb when it comes to the electronics available now!

*edit*

I am probably going to replace my B01 engine with enough simpler low-end engine like the TTR .21. The Tiko .21, the Go .21, and the Ofna Picco 3-port are also options, but the the Picco has a low RPM limit (27k), the Go is out of stock at A-main (which is and has been my point of reference as I find my feet in this hobby again), and the Tiko's reviews arent all that consistant it seems (pretty good overall, but there might be some lemons floating around also).

In general I am trying to keep a budget in mind as I start off in this hobby again. I am not trying to cheap out, but I dont want to just spend a bunch of money right off the bat when I dont need to.