A T5 HO 54W tube is 4460 lumens http://www.gelighting.com/LightingW...LongLast_Lamps_Data_sheet_EN_tcm181-12831.pdf
so unless you are desperate to have T5 for some reason, you will be far better with the T8s. Much cheaper fittings and the tubes are much easier to obtain.
The HO high output is in comparison to other T5 lamps, which have significantly less light for the same size. They are not directly comparable to T8 or anything else - a 58W T8 cool white tube is about 5200 lumens so significantly better than the T5.
The main benefit of T5 is the smaller dimensions both in diameter and length, and they can be run at higher temperatures - of little relevance for normal lighting in a garage.
so unless you are desperate to have T5 for some reason, you will be far better with the T8s. Much cheaper fittings and the tubes are much easier to obtain.
The HO high output is in comparison to other T5 lamps, which have significantly less light for the same size. They are not directly comparable to T8 or anything else - a 58W T8 cool white tube is about 5200 lumens so significantly better than the T5.
The main benefit of T5 is the smaller dimensions both in diameter and length, and they can be run at higher temperatures - of little relevance for normal lighting in a garage.