Losi Baja Rey Upgrades? (servo, shocks, etc)

[bo_rc]

I found a couple threads that answer some of these questions, but some are old with outdated part #'s or not specific enough for me to actually track down parts (I'm pretty new to RCs)

Just got a Baja Rey and after putting the first pack through I want to do a few things but need help finding the right parts. I like to order from Amain as I'm close to their warehouse and so things get to me fast.

No long explanations are needed, just recommendations!

1. Stiffer suspension
I have a SMC7400mah 3s that weighs things down and the truck sags to almost full travel. I saw that Proline Powerstrokes are good, looks like there are two kinds, front and rear. Will those fit as is? Other options that also have options for different spring rates?

2. Faster servo
The stock one is awful, can barely steer. Is this or this one good?

3. Wheels and tires
Doughnuts like crazy and it's actually wearing through the body in the back Any suggestions to solve that? I'd prefer beadlocks, I'm terrible with glueing tires.

4. Locked rear diff (I have the Rapor version)
I think I want to lock the rear axle, whats the best lockers? I saw somewhere SSD makes some?

5. Other strength upgrades?
I've seen that eventually getting a new alloy front bulkhead and rear diff housing is good, and new bearings (Fast Eddy?). Anything else I should be considering? Alloy A and trailing arms?

Thanks all!