<ul><li><a href="http://www.roarfilter.com/">Roar</a></li></ul>

check out BMC filters they have a CDA that fits in the 2.8.. the 85-150.. looks the most promising from what i've seen and tried

2-2,5 years ago I was in contact with them regarding buying it.
1st thing I did not like is that they were not able to give me proper buying/selling documents like profoma Invoice- to pay by bank wire. Than Acc. was personal one not from Co. than they were very slow in answering.
2nd- I read on few forums that people sent money and never received their purchase.

I would recommend only personal visit and purchase, not buy CC or PayPal.

Otherwise,
+ Filter material is easy to be cleaned.
+ No oil to be used.
- High air flow.
- Low dust-filtering capability.

Like an option you should consider Raid HP filters. They are made from same type of material and also have protective box (Aluminum and I heard- from recently also in CF box).
Also my personal favorite, BMC CDA.