[TR] Suspension bushings redux

[Brian.L.Jones at gsk.com]

Listerati,

I have been reading through the archives in preparation for a renaissance 
of my TR4's front-end suspension.

New springs are necessary, new shocks are a possibility, new bushes are a 
certainty.

>From what I have read, replacing with rubber bushes is out of the 
question. Of the alternatives, some have chosen bushings made from a 
nylon-type material, some have opted for polyurethane, and a cosmopolitan 
few have combined them (poly-lower and nylon-upper, as I recall).

My questions:

1. Have those who opted for nylon found the feedback too harsh for regular 
road use?
2. Have those who opted for polyurethane found the wear excessive?
3. Have those who combined bushings achieved what they sought?
4. For those who fitted the bushings themselves, is the reaming achievable 
using hand tools, or is a lathe essential?
5. For those with polyurethane, did the application of grease prevent 
squeaking? 

I don't race, though I'd probably describe my street driving as 'spirited' 
(a brake booster is also on my list). I'm leaning to all-polyurethane, 
pending your insights.

Also, who do the list see as the bushing supplier of choice? TriumphTune, 
BPNW, Moss, Revington, TRF all get regular mentions.

Many thanks,

Brian in Valley Forge
Triumph TR4 1963 CT14455-L