John
Just a word of advice. Be aware that a laser is not a be all and end all collimating tool. A a rule, I only use the laser for final tweaking, it has a role but only for the final check.
If you think about it it is perfectly possible to get a perfect looking alignement wit the laser, but have the secondary not even remotely centred under the focuser. Personally on my 12" I use a collimating cap, cheshire/sight tube and a laser and follow this little guide
http://www.astro-baby.com/collimatio...on%20guide.htm .
I then use the laser to check collimation quickly before or during each session and do major checks every few months. Obviously if I do any work (installing a focuser, washing mirrors etc,) I collimate from scratch.
Malcolm