i had #2130 mounted then used #2451. Both sets worked very well, P/S is bolted to front of the block, no bracket going to exh bolt.
The only two brackets I have is the cradle bolted to the front two bosses, drvr side, berween the water pump and oil pan rail. The second bracket is the adjustable one and it bolts between the eng mount and eng mount bosses, very slick.
A/C, you're on your own, but I would suspect somebody makes a bracket to bolt to exh bolts for holding up compressor.
Personally, I'd go for the 2451, smaller dia for street driving. Maybe copper gaskets to seal flange to header to prevent leaks. With Hooker's, it a full time job to prevent leaks, or repair them I should say.