Which types of airspace are depicted on the En Route Low Altitude Chart?

You have filed an IFR flight plan with a VFR on Top clearance in lieu of an assigned altitude. If you receive this clearance and fly a course of 180°, at what altitude should you fly? (Assume VFR conditions.)

When an aircraft is not equipped with a transponder, what requirement must be met before ATC will authorize a flight within class B airspace?

In addition to a VOR receiver and two way communications capability, which additional equipment is required for IFR operation in Class B airspace?