I use foam rollers for everything except the first coats since I believe it adds too much air to the wet out coat and that air can get trapped in the weave leaving white sparkes I use rollers sold under the West epoxy name, but I have seen rollers sold in local paint stores that are similar. You will want a very thin foam on a cardboard or plastic core. If they come in 7.5 in length, then I cut them in half for full deck or hull coats and usually use only one half per coat, maybe two on a larger canoe as they will tend to get soaked and come apart. For smaller areas such as seams or cockpit I cut them into 1-2 in pieces. Roller covers from West are seen on their web site at http://www.westsystem.com/ss/mixing-application/ The roller that you show are mostly for strand mat in which multiple layers are applied at once and you need to roll out the air trapped between layers and to push the mat onto the project. A simple squeegie will get the air out on one layer of cloth.

You will not be able to clean the roller covers. I guess you could, but they will likely fall apart with solvents or take more solvent in dollars than just purchasing a new one. If you cut them in half and smaller pieces I suggest that you will need at least ten individual covers for a full boat, in and out.

I have more info on my web site about fiberglassing and using rollers at http://www.orcaboats.ca on the how to page