I have a P229 in 9mm. I love it, it points extremely well for me, I don't think its nose heavy personally, if you have a fully loaded mag inserted, I can balance it with a single finger under the trigger gaurd.
The P228 is the US military conceal carry sidearm, the M11. Special forces units like the Navy Seals use them, some not all though. I believe the reason new ones are hard to find is that Sig is filling all the military and police contracts and is currently not selling them to the public. You can certainly find them, generally used but on occasion NIB.
But I say get the P229...seriously 3 oz is for the average person not a concern. It also has a better slide and if you get a two tone version you'll have a great looking weapon and a very durable nickle finish.
~bamf