I’ll do my best to answer.
First clutches: There are many options, but most folks run either the Premier Stinger or the Hilliard Flame. You can find internet discussions and FB threads in the 100’s of comments around which is better. I think at this point, I would just say it is personal preference. We use the Flame for its simplicity. It seems to be the most popular (maybe 60-ish % of the market). Inboard vs outboard has to do with the which way you mount your clutch. Inboard has the drive gear against the engine. Outboard has the drive gear furthest out on the crank. You pick which one allows the best clearance for your engine/mount/chassis/chain/gear combination. Again, there are arguments all over the internet about which one is better (outboard gives more clearance vs inboard causes less stress on crank). I have run both with success.
Now, for the fun stuff. The 206:
A 206 in a box will need quite a bit of assembly. Theoretically, it is as simple as exhaust and fuel lines and let her rip. Set the float height, set the lash and you are optimized, right? There are some more nuances to it. This is why folks pay “builders” to do the work. Let me give you an example. Do you know how far on to put the muffler onto the pipe to give you the most power? Do you know what coil gap or ignition timing gives you the most power? Or do either one of those really even matter?
You will get a ton of answers. Many people will say: I took it out of the box and won with it (and i have seen this done). Many people will say “You have to run this guy’s $1400 engine and its worth 10% more power” (and i have seen these people win, as well).
I try to give newbies this answer. How much do you want to learn and how much peace of mind do you want? Do you want to learn some DIY stuff and just hone your racecraft? Buy one in a box and tune it yourself. Do you want the peace of mind knowing your stuff is as good as anyone elses and jsut want to pull the string and go? Then find a “builder” you trust and support them.
Even though I sell race ready and dyno tuned 206s, I think you can have “success” (this is different to different people) either way.