I have the V8 but speaking for MSD brand, I recently bought MSD wires, best I've ever used! Had fully adjustable boots even though they appear straight only. Nice quality wires inside and out. I also have the cap and rotor which seem well made with the brass terminals as opposed to the zinc colored Motorcraft version.
The only complaint I have is the MSD coil I had bought barely made it a year, but I noticed there seemed to be less pep when going back to a cheapo coil afterwards. So maybe another MSD coil in my future to make double sure.
Just a heads up MSD does not make a distributor cap for the 300 I6. MSD everything else will work great though. Just get a distributor cap and rotor with brass contacts (non MSD) and all the other parts MSD and you will be golden. ACCEL makes a brass contact distributor cap and rotor that works well with the 300.
I bought a distributor cap and rotor button with brass terminals on both made by Taylor and it made a huge difference. I'm getting ready to dump about 70 bucks into Taylor Cable plug wires that are 8.2 mm and only have 50 ohms of resistance per foot.