Metro Flashed Mogul (help better ROM)

[Hunkpowers]

Hope im not being a retard.
I have a htc mogul that has been flashed to metro pcs.
I new at the phone game and after reading a lot I am still very confused.
Can I update the rom to a better version (if so what version is suggested)
and will I have to flash the phone again? I have working internet and phone but no GPS or picture messaging. I would like to learn how to do some tweeks but am still just a beginner at this point. Please direct me to threads I may have missed about this. Thanx

model ppc6800sp

rom 3.35.651.2

radio 3.35.04