The arms (above) I recently devised for an American priest who lives and works in the USA but who, in addition to his pastoral responsibilities at home, was honored by being named an Honorary Canon of the Collegiate Chapter of the Basilica of St. Florian in Krakow.
The arms are:
Quarterly skewed to the dexter Gules and Argent; at the cross point a cross of St. Florian counterchanged Or and Azure; in sinister base above a mullet of six points Or an open crown Argent. Suspended below the shield is the badge of the Equestrian Order of the Holy Sepulcher. The shield is ensigned by the galero of a Canon Sable with cords and six tassels in two rows of one and two respectively Sable. On a scroll below the shield is the motto, “Fiat Voluntas Tua” (Let it Be Done According to Your Will).
The principal colors of the field are the Polish national colors and the division of the field alludes to the off-center cross found in the arms of St. John Paul II (who raised St. Florian Church, his own first priestly assignment, to the rank of a basilica). the cross associated with St. Florian himself is superimposed over the cross point and is colored in blue and gold counterchanged to avoid the tincture violations. These colors are also found in the arms of St. John Paul II.
In the lower right there is a six pointed star to symbolize Our Lady and it is crowned with an open crown alluding to Mary’s Queenship, the patroness of the armiger’s home diocese.
The black galero with black cords and six black tassels indicates the bearer is a cleric with the rank of Canon, in this case, a Collegiate Canon. Being a Knight of the Holy Sepulcher he also chose to display the badge of that Order pendant below the shield from a black ribbon.
EXARANDORUM 
Clerical (priestly) members of the Equestrian Order of the Holy Sepulchre of Jerusalem are understood to be titular canons. I presume the same is true of priest-members of the Sovereign Military Order of Malta. As titular canons, should such members also use six black tassels? Or is this reserved to collegiate/cathedral canons (and canons regular) only?
The short answer is that I do not believe so. There are several reasons for that. The designation of priest members is not universally being observed not just from country to country but from Lieutenancy to Lieutenancy. It is not, for example, a category mentioned in the most recent Constitutions of the Order. In addition, as I understand it, this designation is a relatively recent innovation brought about by the recent increase in clerical members. As I have been given to understand the priest members are being called titular canons because it is considered inappropriate to call them knights. So, the designation as titular canons is more seemly for those who, by their state in life, cannot fulfill the obligations of knighthood. Nevertheless, the brief of appointment from the Grand Master still calls the priest member a “knight” (equitem) so the designation of titular canon may simply be semantic. There are actual Canons of the Holy Sepulchre and Honorary Canons of the Holy Sepulchre both of which are appointed by the Patriarch of Jerusalem. I know that while this other designation was being discussed the late GM Cardinal Foley argued that only Knights Commander who were priests should be considered titular canons. So, I believe that being invested as a knight of the Holy Sepulchre does not mean an armigerous priest may use the galero of a Canon. The hat with six tassels is most appropriately used by Canons Regular and Secular Cathedral or Collegiate Canons. One last word about the comparison to the Order of Malta. In that order priests are not permitted to be admitted as Knights. They serve as Chaplains TO the Order, not Knights IN the Order so they are not designated as titular canons by virtue of being in that order. Unlike the EOHS the SMOM allowed for a different designation for clergy (Ch.M.) as opposed to lay members (K.M.). If, in the end, the Order of the Holy Sepulchre would clearly define the status of priest members and if they affirmed that all priests in the Order are titular canons automatically and this is to be observed throughout the Order then it could be argued that the galero of a canon could be used by any priest in the EOHS. At present such clarity does not exist.