Laser Engraving on My Kossel Clone/ Expanding My Build Area

[ctcollins9]

Hello,
Thank you for the link, very helpful. I am very aware of wearing eye protection, but thank you for being concered. It looks like I need at least a 300mW laser as the person in the link you gave me had.

Here are the options in which I think I may purchase (please tell me which one you think is best):

1) I could get this housing:
http://m.ebay.com/itm/111068814975 and a laser diode: http://m.ebay.com/itm/110896818957?_mwBanner=1 (I can buy any mW version of this I need)

2) This is an infrared 300mW laser: http://m.ebay.com/itm/191351985912?nav=SEARCH.

And, if I used either of these options, which other things would I need if anything. We have a fairly old computer tower, I may be able to find a diode in that and just purchase the housing.