Hello Naz,
You can place a standard power bar in the back of the rack, but, beside a little surge protection and filtering that the Monster power bar and Furman Rack have, the Furman has one feature that the Monster doesn't have... the E.V.S. (Extreme-Voltage-Shutdown). That feature will not allow a voltage of greater than 133 VAC, (a reverse brown-out), to pass to your equipment.
A reverse-brownout is rare, but, with the Furman installed you don't have to worry about it. If you really need the space, the power bar will work for you and will probably never cause a problem.... (you probably have a pedal-board powered by a Voodoo Lab power supply that doesn't have most of that protection)
I hope this helps
Seeya
Joe