I don't think there is a "best" kit per se, but imho I've always favored to use the "factory/oem" style bracketry/pulleys, etc. because those are made to pretty much last the life of the vehicle, and "engineered" to allow for simple belt changes, maintenance and "off the shelf" replacement parts like the belt, tensioner, etc. at most any local auto parts house. I have several friends with high priced aftermarket systems which are nice to look at, but have allen/torx head screws, and proprietary hardware/tensioners that are nothing short of a nightmare to get the belt on/off in the shop, much less on the side of the road in an emergency. All I need is a breaker bar, and the spare belt and it's on/off in a few minutes.
It's entirely up to you what you're looking for in terms of "best" (looks, functionality, ease of maintenance..?), and you should shop around based on your preference, but definitely have a look at the GM Perf Parts systems (offered with and without air), or look for perhaps a system you pull off a used BB TBI truck from 80s/90s at a salvage yard to get all the bolts/brackets/pulleys, etc if you already have other components to save some $$. You can clean up, and powder coat/paint everything to look good as new. I've used the thirdgen camaro (ie; 88-92 Camaro) style serpentine on my 383 Small Black for over 30yrs, different configs and have never had any issue with it other than to replace the tensioner once, standard readily available ACDelco part.
Simplicity and serviceability is your friend in hot rodding, again that's my humble opinion, YMMV. Best of luck with your (re)search!
With A/C
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Without A/C
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Here's the pic of the two systems from the GMPP catalog with references to the individual component parts.
Here's a link to Summit with some filtering to help get you started on other aftermarket options:
Find CHEVROLET 7.4L/454 Chevy big block Mark IV Accessory Drive Systems big block serpentine belt system KEYWORD and get Free Shipping on Orders Over $109 at Summit Racing!
www.summitracing.com
Here's evelotions of my original TPI (Camaro LB9/L98 Serpentine system over the years)
The original TPI swap back in 1989 or so....
Added Paxton S/C so lost the driver side bracket (but didn't throw it away, lol)
Switch EFI over to Holley StealthRam, still with Paxton
This is the current setup, lost the Paxton, went back to N/A and went back to the OEM Driver Side Alternator/Power Steering Bracket. I was able to even upgrade to the 150A AD244 (2000-2005 Silverado) Alternator by simply enlarging the mounting hole for the CS130 Alternator which (IMHO) are crap. (rear bearing sucks, even the 10mm H/D doesn't seem to last but I digress)