No, use the base part & classes specified (e.g. BC550 - class C). E.g. in the case you ask about either BC550CTA (ammo/tape) or BC550CBU (bulk/loose).
Curious, how many builds do you have under your belt? The CTH is an intermediate level build, *lots* of parts in a tiny space, and misplacement / misalignment of any can ruin your day. IOW IMO would not recommend CTH as a first project.
Edited by cfcubed - 5/4/15 at 3:30am