Newbie,
Go for it and have a great time. There is no shame in being guided up that big mutha in my opinion. I think with your experience it is probably a very wise decision to make. Just do some training and you will have a wonderful experience hopefully. Stick to your hiking and get out as much as possible. Remember the true experience lies out there following those original legendary footsteps in pure enjoyment as well as a certain amount of controlled safety which is more likely to be your case. I cannot stand going up there with some gung ho summit or plummet person in my party that may ruin my experience.
Good luck,
-Cpt