Currently in an 03 530i, thinking about a 94 530ia w/ 84000 miles , What are the issues with the nikusil/alusil blocks and where can I find more info?

GOOGLE! :confused

"The BMW M60 V-8 (http://www.bmwworld.com/engines/m60.htm) and BMW M52 6-cylinder (http://www.bmwworld.com/engines/m52.htm) engines (the M52 Nikasil engine never went to the USA) with Nikasil cylinder bore linings are particularly vulnerable to fuel (gasoline or petrol) with a high sulfur content.
The sulfur in the fuel breaks up the Nikasil lining in the cylinders, thus causing a loss of compression. Once the lining is damaged, excessive bore wear of the soft, underlying alloy occurs very quickly. Some Nikasil engines have failed in as little as 30,000 miles. And the effect is cumulative, so if the engine has ever been run on high sulfur fuel, the damage may already have been done and premature bore wear may result.
Some symptoms of the Nikasil problem are rough running at idle and difficult cold starting, both due to loss of compression. In severe cases, the loss of compression is so bad that the engine loses power. Oil consumption increases dramatically as oil is sucked up the side of the leaky pistons. In extreme cases, the compression decrease is so severe the car will not start in cold weather, especially M52 6-cylinder engines." - BMW World

"The BMW M60 V-8 (http://www.bmwworld.com/engines/m60.htm) and BMW M52 6-cylinder (http://www.bmwworld.com/engines/m52.htm) engines (the M52 Nikasil engine never went to the USA) with Nikasil cylinder bore linings are particularly vulnerable to fuel (gasoline or petrol) with a high sulfur content.
The sulfur in the fuel breaks up the Nikasil lining in the cylinders, thus causing a loss of compression. Once the lining is damaged, excessive bore wear of the soft, underlying alloy occurs very quickly. Some Nikasil engines have failed in as little as 30,000 miles. And the effect is cumulative, so if the engine has ever been run on high sulfur fuel, the damage may already have been done and premature bore wear may result.
Some symptoms of the Nikasil problem are rough running at idle and difficult cold starting, both due to loss of compression. In severe cases, the loss of compression is so bad that the engine loses power. Oil consumption increases dramatically as oil is sucked up the side of the leaky pistons. In extreme cases, the compression decrease is so severe the car will not start in cold weather, especially M52 6-cylinder engines." - BMW World


That sums it up very good.

http://www.koalamotorsport.com/article-m60v8.asp

Oh and rough idle does not always equate to nikasil problem.