I'm looking into adding a supercharger to my 91 Camaro and I have a few questions. First, how difficult would it be to install? Is it something I could do myself for a weekend deal? What are some good affordable superchargers?

 

Trust me there are no afforable supers that work.
RSM I think they are.
They all go for $4,000-all most $5,000 + plus headers.
The 4k kit gives like a 60hp boost and the 5k kit gives a 80-90hp bost.
The do look easy to install, a weekend maybe. There quality is questionable.
The restrictive cast Iron cylinder heads on the 3.1 wouldn't help a super charger very much.
A good super charger engine needs a great flowing intake to make use of the pressurized air. That's not a 3.1 at all.
You would have to have headers. Because the stock exhaust can't handle the stock engine out put.
I have figured out that these engines would make better nitrous and turbo (in that order) engines.
I don't think any one has made a turbo kit that has made much less than 100hp over stock. I don't think any one has made less then 260-270hp first run with a turbo.
There is tango he makes 60*-V6 turbo kits for around $3,000 I think.
I am building my own twin turbo, so far up to $1,850 and that includes a lot of non directly related to turbo stuff, turbos plus one extra turbo.
Its all on the car domain site. Heads, cam, valve train, fuel system, ignition, turbos, intercooler, intake modification, exhaust (comeing soon) and more. All work done by me, that is why it cost so very little for so much stuff. My labor cost are free to me.
$1400 was the minium cost to get it in the car and running, but that dosen't mean running right or at full power (with out a working exhaust).

 

Wow, that is more than I paid for the whole car. Forget that.