if you mess with 48 size even on the cheap its gona cost more than a EDF I think. I know unitedhobbies.com has some alright EDF's and motors for fairly cheap. not the greatest stuff but plenty fine for this kind of messing around. anything around 3 inch is gonna put out as much as a 25 type fan too except with more efflux.

https://www.unitedhobbies.com/UNITED...idCategory=153


Barry