Getting started in .25 midgets


We are looking into potentially getting our 5 year old son started in .25 midgets. We plan to take him to the Arrive and Drive at Tri-City next weekend. Does anyone know of a good classified website for .25 midgets? I'm trying to gather information as to annual budget needed to run the car and general knowledge on set up, etc. Any help is greatly appreciated.
I would suggest looking for a 76" long with a kirkey seat and adjustable pedals. Most of the tracks will have a classified page on their website. You can also look on Facebook market place. For a car , pit kart, and some parts around $3,000. Yearly budget to run at one track I would plan around$1,500 - $2,000.
For transporting to and from the track, I assume most used enclosed trailers? What size trailer is sufficient for the car, pit kart, parts, tools, etc.? How often do package deals, car, pit cart, trailer, parts, etc., become available. It seems that may be the easiest way to acquire what will be needed.
Here's the two sanctioning body's. I believe Tri City is usac but Greenville is qma. If they rain out this weekend Greenville has there arrive and drive on the 14th. They both will have classifieds and links to there tracks. There will be some complete sell outs. The first year we ran we hauled everything in a 8' truck bed. The tools you will need is very minimal.
I will definitely look into the book. Are there any good websites to get general information. For example, some cars have titanium axles. I'm not sure if that's good or bad. At this point I'm just trying to learn as much as I can so that if we move forward, I have a little bit of an idea of what I'm looking for.

Are there any particular brands of cars to stay away from? I don't see many cars for sale and most are rollers. I think I would prefer a complete package rather than piecing the car together especially since we are new to this. Our son is doing the Arrive and Ride this weekend so I guess we'll see how that goes and go from there.
As for the axles it really comes down to your budget. We ran alluminuim rear and steel for the front. At your boys age it will manly come down to how your son drives. We ran a Stanley, Bull rider is also a good one. Can't think of other makes. You will have a spec motor to run at first with a restrictor plate. Most of the people at the track will be helpful also with info. We have been out of them for about 8 years. We take the grandson over to Greenville Saturday to try them and may be looking ourselves.
Here's some more makes I thought of. Ashley, Nervo, and Boomerang. When we where running Nervo and Bull Rider where the top two. Most of the chassis builders will have info about their chassis on line.