OZ rims for 01 e53, 29mm offset?

[Phr3d]

Tire Rack has a set of OZ rims that I like, and spec them as a package for the 01 e53 3.0i 5m std.. then I see the offset is 29mm vs my present 40mm.

First question, does OZ still make a fine aftermarket rim, or should I stay in ronal/borbet-land (can't afford BBS, nor the tires for large wheels)

As a victim of balance/other issues with prior wheel purchases, and as someone who has had damned-poor luck completing the X before I posted pics, is this something that I can trust Tirerack about? seems a substantial difference.

Or do I just not understand offset correctly.. I'm pre-shopping for next summer, putting conti's on the factory uglies for keeps..

thanx

P.S. at the risk of sounding more n00b than I am, we had some difficulty with the short 1st gear in our baby, very un-BMW, and seemed to be aimed at 0-60 times and dragging small ranch-homes from their foundations. alternatively, I've howled about why they didn't just put in the big six and presume that it made it too competitive with the 4.4.. a 3.5-3.8 m5 or m6 would be a hoot <sigh>. (so can I bore this puppy out or head it? ah shyt it's the baby-six).
So the exhaust tips looked horrendous and I managed to find a 4.8i set to replace it - the take-up in 1st is much improved.. or is it just us getting used to it.. so the 'additional question'.. can the diff gears be changed to raise the final drive? In my e12 I woulda' done it in a second, but with 'puters and AWD.. not sure what is involved.. (sure hope JCL sees this)