Can't go wrong with the Traxxas Slash , it's a great beginner set comes with everything you need to get started . Above that would be the Traxxas Slash 4x4 , same deal as above but has a better chassis and 4wd . After that anything from Team Associated or Team Losi are pretty much the top of the food chain .
When I lived in Tempe, AZ I raced RCs at the Scottsdale RC Speedway. They held a big State Championship race there every year back then... I would imagine they still do, it was pretty cool with all the big sponsored pros coming into town for the two day race. I came in 2nd in the Novice Truck division with my Team Associated T2 truck after being t-boned in the first turn then driving back through the pack!!!
Nitro is kinda slowing down as far as 1/10th scale with all the brushless / lipo set-ups out there . Your best bet would be to either sell the Slayer and get a Slash or get this conversion kit
TowerHobbies.com | Tekno RC Brushless Conversion Kit Revo/Slayer
Sadly, nitro racing is dying. No one in Nor Cal races them anymore. Brushless/Lipo just has too much going for it now.
I've raced a couple of everything. My avatar is my latest Losi SCTE 4WD. I gotta say, it's probably my biggest let down. Poor parts quality, hard to set up, ill handling. I'm not a fan. I built it with the best of everything and it still isn't great. I turned faster lap times with my 4WD Slash.
I'm going Kyosho or AE for my next SC truck. I've had awesome luck with Kyosho. Parts are a little harder to come by locally.
I might convert my Kyosho nitro truggy to brushless.
warehouse 3 and srs are the places to go. srs is kind of jackass status these days, but the dudes at warehouse 3 have it going on. indoor, air conditioned, well stocked for parts, frequent track changes... unfortunately SC is kind of a dead class these days. once upon a time we would get 3 or 4 heats of them but its pretty much just the novice class anymore. and if we do get a heat or two, generally the racing looks more like demo derby than actual racing.
the problem is that srs opened up like 5 miles from the only other indoor track in the state (yea, total dick move) and now the car counts are down at both places. 17.5 buggy is pretty much the biggest class with any consistency, and even then its a cheaterfest. at w3, they started running a 'pro' and 'sportsman' 17.5 buggy and its been wildly popular. the rest of the classes fluctuate, depending on what the 'cool' thing to race is. personally, i own a 4wd buggy, 17.5 sportsman buggy, stadium truck, and SC truck (plus an assortment of motors/esc/batteries) so i can kind of keep up with whatever class has it going on, even though i usually only race 1 class.
if you have any questions, just hit me up. i can get you pointed in the right direction with setup/tires (we run slicks, and i'll tell you how to properly sauce them) and stuff.