eVent Jackets and top of the line Goretex Jackets are expensive. Lowe Alpine used to have Ceramic Triple Point Fabric which almost as effective and these jackets can be had for a very reasonable amount.

For example,

http://www.sierratradingpost.com/search/...scriptions=True

I seem to remember that Columbia used there own material called Omni Tech or Omni Dry (similar in performance to SympaTex), which were reasonably breathable in colder conditions but weren't as breathable as say Goretex XCR, Paclite or Ceramic Triple point. eVent is probably the best for breathability but it is not as durable. All are pretty much useless above 15-20C temperatures especially in humid air conditions.

You may be able to get a good Goretex Paclight Jacket on sale from last season.

Typical Goretex Paclite Jacket

http://www.golite.com/product/proddetail.aspx?p=AM1735&s=1

Montane eVent Jacket

http://www.winwood-outdoor.co.uk/acatalog/Men_Montane_Jackets.html

A tight weave cotton garbadine jacket which has been treated with Grangers or Nikwax TX10 cottonproof might be an idea in warm humid conditions but would only be showerproof and windproof but not completely waterproof.

http://www.militarykit.com/products/jackets/british_army-type_sas_windproof_smock.htm