Honestly unless you're a pro I wouldn't bother with Snap-On. They are geared towards pros and priced accordingly. You get better service from your truck guy, but you don't have a truck guy. Also unless you can prove purchase new there is no warranty on Snap-On tools unless you have a pro friend with a good relationship with his truck guy. I'd save your money and buy Wright instead. They're really nice, and priced at about the same level as SK instead of Snap-On.
There are a few things that Snap-On does better than most anyone (or plain anyone) else. Combo wrenches aren't one of them, unless strength to weight ratio is important to you. The Wrights are a little heavier, but IMHO feel better in the hand anyway.
Things that Snap-On does really well: Fine tooth ratchets (Dual 80); ratchet and breaker bar handles (nobody else's feel as good in my hands as Snap-On does; a similarly shaped GearWrench breaker bar is way heavier than Snap-On); supposedly ratcheting bit holder screwdrivers, although I'm still limping by with my Craftsman clone.
Wright is IMHO the head of the class with open end wrenches. You'd think that Williams would be as good, being a Snap-On brand, but reports say that they aren't. I have a few anyway that I got on clearance, they're fine, but you did say *best.* Only thing that frosts my cookies about Wright is they don't offer a 9/32" or 11/32" combo wrench, and I just used the 11/32" the other day so don't tell me it's an obsolete size!
Sockets, I like SK, although Wright, USA Williams, etc. are probably all excellent choices. Snap-On is of course excellent but pricey. Harbor Freight Taiwan-made Pittsburgh Pro impacts are good and cheap; I bought Snap-On used for metric because the PP set skipped sizes. Not an issue with the SAE fasteners on a 50 Caddy though!
I just started a thread about screwdriver bits, and the consensus there seemed to be PB Swiss for most stuff and Vessel for JIS (which you won't need.) Williams makes separate screwdrivers that look for all the world like the old Snap-On black hard handles but with a Williams logo instead, if you prefer separate screwdrivers those are a great value but unfortunately they don't offer Pozidriv if you need it (not sure if Caddy ever used it, but Studebaker about that time used Pozi for the door hinge screws, which is actually what prompted that thread, as I was holding a Williams Phillips driver in my hand and thinking that I needed some Pozi drivers.)
If you don't have a hand impact, that is another tool you'll need... I used a parts store "blue box" one for years (they still sell them) but the Lisle one I replaced it with was way better. The Snap-On one that I replaced the Lisle with is the best I've used. The Lisle bits didn't last...
if you'll be working on brake lines/hoses, you'll want a GOOD (not CMan) set of flare wrenches. Snap on are of course excellent, but I have a set of SKs for metric. I haven't used them hard yet so I can't say if they're as good as Snap-On yet or not.