I am helping a friend who wants to stain his garage floor (rented space) and I have never stained concrete.  He is not trying to create a masterpiece; he only wants uniform color at a good price point.  My first question is acid versus acrylic stain; what is the best and fastest way to go?  My next question is sealer.  It looks like most concrete sealers are topical; must I use a sealer specifically formulated for concrete?  I bought several gallons of scc color enhancing solvent penetrating sealer that I don't use much and I would like to use it.  Would this create a problem?  Thanks in advance for your help.