I'm switching to shorter cranks on my Trek 7.4 FX WSD 9-speed hybrid which currently has 26-36-48 steel chainrings. I was recommended cranks which come with 22/32/42 steel rings, with a 44t alloy ring as an optional upgrade.

As I'm a total dunce with gears, does this mean I could choose from either:

22/32/42 (all steel)

OR

22/32/44T (where the 44T ring is alloy. What does the "T" mean anyway)?

Which would be better? As to how I ride, I prefer spinning and use the middle gear (36?) 90% of the time. I only ride on paved roads, although I do like having the option of a bigger gear to "work up to" and for working out on my indoor trainer (a CycleOps Fluid Pro). I'm not very athletic and I need to lose 10 kg of weight, if that counts.

Which would you recommend I go with?

Thanks in advance