Are they different types of deacons?
Yes. In the Syriac Orthodox Church there are various orders of the deaconate. The order of the deacon can be recognized from the way they wear their stole (uroro). The orders of the deaconate are:
1) Singers (mzamrono) wear the kutino without the uroro.
2) Readers (qoruyo) wear the uroro in the form of a Cross.
3) Subdeacons (apodyaqno) wear the uroro folded around the neck.
4) Deacons (shamosho) wear the uroro over the left shoulder, on either side like wings.
Only the full deacons (shamosho) are allowed to read the Gospel during the Divine Liturgy and server communion. Now days, even full deacons don't read the Gospel during the Divine Liturgy during regular Sunday's. The priest himself will read the Gospel. The feast day of St. Stephen (the first among the deacons) is the day when the full deacon if present during the liturgy will read the Gospel.
There is a fifth order namely: Archdeacons (archedyaqno). Archdeacons are usually priests. It is a title given to the head of the priest who helps assists the Bishop in the running of the diocese. In the present day, there are not many Archdeacons in the church. If my understanding is right, in the Catholicose faction of the Syriac Church in India there is an Archdeacon. I will let Suraj confirm this.
At the very end of the following link, you can see photos of how each order within the deaconate wears his stole.http://sor.cua.edu/Vestments/index.html
Mathew G M