I am not sure that I understand the questions I am thinking that you are asking about something like GFP or one of the variants. To view GFP, most people use FITC filter sets and you will also need fluorescence capabilities. From your second question I don't think it is too challenging to express GFP or a similar protein, and view many interesting things depending on what the protein partner is, what is does and where is goes etc. If you are interested in long term imaging you will need an on-stage incubator. I have included a website here that will give you information of a great set-up for the work you are interested in doing. (http://www.lifetechnologies.com/us/en/home/life-science/cell-analysis/cellular-imaging/cell-imaging-systems/evos-fl-auto/evos-onstage-incubator.html)