Re: Tom Welling - Clark Kent/Superman : The Man Behind The Cape
Smallville series was loosely inspied by Donner's take, so the Suit was of alien origin given to Clark in Fortress, it was not home made like Lois and Clark series suit.
So they has two options either use Reeve suit or SR suit. Dean Cain's suit (Lois and Clark) was out of question.
Creative team decided to use SR suit as Welling was going to be shown in CGI- Superman in the finale. (IMO.)