I have the gowesty +1.5" progressive springs.  The springs seem fine,
but I'd recommend against the lift unless you are scraping bottom
off-road.  I was, and I'm mostly glad I did it, but I seem to be
paying the tax in extra CV and upper ball joint wear.

I did the rears first, and was driving around like that for a year or
two, and it did give the van a pronounced nose-down posture.  1.5" is
a lot.

Can't comment on the swaybar, but I did recently replace my worn and
incorrect sway bar bushings with new ones from T3, and, like Eric say,
WOW, what an improvement even getting the stock swaybar working as it
should.

-Alex