PETE....hold your horses and read the following.
If you are planning to race the upcoming GT type event held by LHR and even the MWS (Mid West Series that you should consider as well)....your car must be in STOCK form of shape. All these carbon fiber, Titanimum, or whatever 2-speed upgrade are most likely ILLEGAL for you to race, unless they decided to add a "OPEN" class, which I don't see that going to happen (at least, not MWS)
Now...I too asked this question last year because I was planning to race these 2 events except I am expecting a new daughter this summer (which is super good...
) DM1-SPEC RTR is what I was planning to get over the IGT1 or IGT2 from Kyosho. Like above mentioned, DM1-Spec 2-speed is a better build unit, then the overall car design is a little better. But the key you should get the RTR version is, that FORCE .28 pull start engine is probably 1 of the best/fastest unit that you can get in the market that is included as a RTR engine and it is LEGAL.
You cannot go dumps in a NOVA ROSSI pull start and call it LEGAL....it is not up by you, it is the LHR and MWS decision...but if you are showing the car that is originally RTR...most likely, that engine will be LEGAL.
Force .28 is easily $175 new....Dm1-spec KIT = $355...DM1 Spec RTR @ Al's Hobby Shop...$450. You can use the stock servos and such, just add in your radio....
But I know LHR will get their rule setup very soon....another thing you need to look around are TIRES...they need to run SPEC tires, that means, only certain brand and compound of RUBBER TIRES are allowed, so does MWS.