12v30a spdt relay tripped by 5v

Tried searching and didn't find quite I was looking for.

I have a 5v output that I need to use as a trigger for a 12v30a relay.  I've been unable to find a relay that will pass 12v30a through but have a 5v coil, and I'm not sure how to properly wire up the transistors and resistors to make sure it doesn't explode.

Here are two options:

Get a 5vdc reed relay from Radioshack.  You can run the 5vdc signal to the coil of the reed relay.  Then, wire the coil of the 12vdc relay through the contacts of the reed relay.

Use a PNP transistor.  Run the 5vdc signal through a ~500 ohm reisistor to the base of the NPN transistor (like a 2n3904).  Ground the emitter of the transistor, and wire the relays (-) coil terminal to the collector of the transistor.  You will want to put a diode across the coil of the relay (stripe facing the 12vdc side). 

There should be 4 pins - two are the coil and two are the contacts. 

Wire your 5vdc output to one coil pin, wire the other coil pin to ground.

Wire 12vdc to one of the contact pins, wire the other contact pin to the (+) 12vdc coil of your relay.

In a perfect world you would mount the reed relay to a PCB, then you could solder a small wire to the board that would connect to the relay wiring.

You would put 12vdc on one of the contact terminals and connect the large relays (+) coil to the other contacts other terminal on the reed relay.