Trimmers are the final essential tool of the professional. Hair Trimmers are all over the place and they can be cheap. Dont make the mistake of buying a retail trimmer. You will always be dissapointed with the results. The typical professional hair trimmers will run you about $40-80 and last you about a year.
Our recommendation would be to stick with the Forfex line and take a gander at their cordless trimmer. Just like the clipper it also goes corded/cordless (plug it in if the charge dies out) but you should have plenty of cut-time with 55 minutes on a full charge. It comes with two blades, including the standard and a T-blade which alone is about $20 bucks. This one will run you about $75 and is worth every penny especially with a 3 year warranty from the Manufacturer.