4th Gen, All OE stock, time to start changing shocks! Help with direction please.

BONE Stock and OE underneath. 2007, SR5, 2wd. 85000 mi.
Front shocks are going out, TIME for UPGRADE! (with blessing from FincMgr)

IDEA: 5100's in front, set to Max. 2.5". First question. DO I NEED to change springs?
How about UCA's? Can I really just slap on the 5100's to 2.5" and get the levelling out I want, at this point?

Part II (in the comping months, not at same time as Front:
REAR - I WILL Be Towing - Occasionally. 3000# trailer(loaded) and my fat a$$ and gear in cargo. (still under 4000#, and under 4500# limit.
IDEA: New Shocks and Springs, WITH AIRBAG Assist.
No Trailer - 5psi air, SLIGHT RAKE.
With Trailer - 30-35psi(whatevers recommended) and still keep slight rake.

Questions:
1 - can I do Part 1 that simply, as stand alone, for now?
2 - How do I achieve my goal of Part II? I am Guessing New Springs and beefier shocks? how about a "variable" spring (can't think of the word!) where part of it is less 'weighted', and same spring is 'beefier' more you compress it... help, my words hurt.

I appreciate feedback and dialog and Dos and Dont's. I read lots of threads, but never found my answer with my goals. Not Offroading, 99% highway, 5% will pull a trailer for campouts, and towing tractor.

 

If the rear is not sagging from age, you can’t lift the front more than 1.5” before you get reverse rake. You really need to do it all at once. If you could find some low mile 5th gen springs and buy them on the bilsteins you wouldn’t be out much more money and have a higher spring rate.

 

Actually - the Rear is 3" higher as it sits - at fender, through CL of wheel, than the front. Thus the +2.5" on front, at first.

Also - PROGRESSIVE Springs!! That's the word I was looking for!!

And besides progressive - would I need higher spring rates than OE on the fronts ?

I am thinking 5100s all around would do the trick.
but-- I can't pull the trigger all at once, nice idea @HarrisNC - but not going to happen. This is a "eventually" get done item.

 

Make sure your lower control arm bolts are not frozen. If you are lifting it 2.5” in the front you will need an alignment and if your bolts are frozen it will cause problems. I lifted mine 3” and upgraded upper control arms just to make sure. Good luck!

 

I put some Tacoma struts with spacers on mine and it lifted front end about 4” which of course had the front suspension “all throwed off”. Guess UCAs are in order now but really wanted to put 285s on it so I’ll see how it goes with the spacers. May eventually take them off but have a toytec spacer that I can try out also that’s a different design that sits on top of spring instead of top plate. But the ride with these springs is very stiff as it is now.
But guess all that can wait until I get it put back together from head gasket job.