4100kV w/ 8T pinion is good for aerobatics since it will give very high headspeeds. if you're not in to aerobatics, you'll want more like 3600kV w/ 8T pinion for more flight time. i am not an expert on brand differences, but i haven't had any problems with himax motors and many ppl have used them for years on all kinds of rc vehicles. unless you buy a cheapo no-brand brushless motor, you should be just fine as long as you buy the right kV and pinion.

if you plan on staying with rc for a while, do yourself a favor now and get a pheonix 10 esc. they're a little more expensive than the rest, but features (esp. castle link) make up for it. even if you decide not to get a phx10, at least make sure you get an esc with governor mode. you'll kill for governor mode once you own a programmable tx, and the price difference between esc's with governor mode and without is very small.

also, esc's over 10Amps are overkill & added weight. my heli draws no more than 7A at the battery at 2800rpm 12degrees pitch. i'd bet around 2A of that is going towards my powerful tail motor, which puts my main at about 5A max. remember, if you buy a 10A esc, that means it can handle 10A continuously, and more for a short period of time (as opposed to 10A peak, 5A continuous, which would actually be a 5A rated esc). so a 10A esc gives plenty of headroom for the inevitable chicken dance, and weighs in at less than half of a 20A esc.

you're also going to want at least a DD tail to handle all the rotor torque when you have a brushless main. if you use heading hold (ie g90), you'll absolutely need DD, otherwise you'll burn out motors at a dizzying rate. i run a geared long can brushless tail on my pro, but that's only cause i'm crazy when it comes to tail performance.

another concern when going brushless that i rarely see anyone mention is blades. imo wood blades are way too flexible for the high rpm you get with a 4100kV motor. it feels wrong when i slam +12degrees at 2800rpm with woodies. i feel like i'm asking way too much and they're going to snap midflight. i use cf blades now, and they track well no matter what i ask them to do.