If I may offer a suggestion, parsimony methods have generally been regarded to be less accurate compared to other methods like Maximum Likelihood and Bayesian.
PAUP* is arguably the most-used, most-cited and best-sold program with a wealth of tree search options and algorithms (also beyond parsimony only) and it 's user-friendly in my opinion. Moreover, the NEXUS file format for input is quite universal and usable in other phylogenetic programs. PAUP* can be criticised for example for having so many options that sometimes you can't see the forest through the trees (no pun intended) and that the program is quite expensive. There are some free downloadable programs. If those that others recommended you are free I don't know; I hope others will tell you in this forum.
I use MEGA 6 (btw, as distinct from the Mega 5, in this version the conversion of your .fas file into the .meg file is not obligatory) and in the majority of cases it is nicely working.
Btw, is anybody familiar with ARB-parsimony tool? I can not properly import the short sequences into existed tree in ARB. Sorry for off-topic...