No, I am not. Here are the ones I am using. They are cheap in price but strong enough to handle the orion .21 I have in my rs4.
URL:
http://cgi.ebay.com/HPI-Nitro-RS4-3-...3286.m20.l1116


John, as far as gear ratio goes, your first gear is off. Here's all you need to know to properly mesh your gears. There are two methods and they are practically the same.

METHOD 1:
add up the spur and pinion gears. The total teeth on gear 1 should equal the total teeth on gear 2.
example:
gear 1: 19t pinion + 43t spur = 62t
gear 2: 23t pinion + 39t spur = 62t
total teeth for gear 1 (62t) = total teeth for gear 2 (62t) ==> PERFECT MESH

METHOD 2:
the total teeth spread in the pinion gear should equal to the total teeth spread in the spur gear
example:
pinion gears: gear 2 (23t) - gear 1 (19t) = 4t spread
spur gears: gear 2 (43t) - gear 1 (39t) = 4t spread
total teeth difference for pinion gears (4t) = total teeth difference for spur gears (4t)
==> PERFECT MESH

The hpi super chassis shouldn't be bad. I don't have it but it should be good because it's hpi (haha). Also, if you want more traction. Try these, they will improve your vehicle a lot but it will look funny if you run a regular body. Kamikazetoysandhobbies.com carries these foams. They are made by Kawahara. The front foams are 30mm wide and the rears are 40mm. They are really wide and will improve your cornering skills.

In your above gear selection, if you are running 17t, gear 1 will not be able to engage because it is pushed off by gear 2. Meaning second gear total is bigger and will create a small gap that gear 1 will not be able to compensate for. Also, I am guessing you have aftermarket tie arms. If you don't, get the gpm version off ebay. They will allow you to adjust camber and toe in. Get the hpi sway bar for better handling. Other than that, make sure everything on your car is screwed on tightly. DO NOT USE THREADLOCKER. THEY WILL MAKE IT IMPOSSIBLE FOR YOU TO TAKE IT OFF. Hand tighten is good enough. Hope this helps. Let me know if you need anything else because the rs4 is an awesome car. It handles very well and will blow a lot of cars away. I personally smoke a lot of people with my rs4. It's fun. Well, have fun with your project.