I don't know how old your Matterhorn is but their highest power snow white Matterhorn in the lug body is pretty bright with a really nice floody beam. Other that that, look into the Pacific or the Baltic and I would go with the highest power offering or possibly one power level below their highest offering. I have two Pacific's, one at the highest and one at their second power level offering. The lower power model doesn't seem as bright up close as the 3Ultra power Matterhorn but that is because of the Pacific's hot spot which greatly out throws the Matterhorn by a long shot and possibly due to color temperatures of the differing style of the leds. Personally, I like the form factor of the Baltic a little better than the Pacific because the Head and the body are much more similar in size and their electronics are the same.
Since I don't own a Baltic as of yet, I can't give you specifics on the beam but Peak could help you out over the phone with that question and the Baltic and Pacific come in a SSCP4 option and you can always add on a Shasta head which will fit on the Baltic body. Both the Baltic and the Pacific lights will be longer than the lug option on the Matterhorn but similar in length if you already have the key chain body on your Matterhorn.
