I am in the process of building my first cnc which will be a flat bed router to be used mainly for cutting surfboards from eps foam however i will also be cutting some wood also. I have been trying to research as much as i can on here and have spoken to a few friends but not really to sure what size spindle i need to be looking at. because of some of the depths i will be cutting i will require quite long bits which i assume will mean it will need a larger collet size. The other thing i will need to have is the ability to adjust the speed during the cut and would all so like the ability to cut mdf and ply wood in the future so having enough power for that is important. I have read a older thread on the 2.2kw water cooled chinese spindles which was briefly mentioned to me but it sounds like it is a bit hit and miss with what you get and that there were some suppliers that were better than others but im really not sure if that would actually be over kill for what i need?
Can any one provide and advise? the only spindles i have really found are the kress ones and the chinese ones on ebay.

many thanks charlie