First of all.. Congratulations!
Yes on the 15 month lease if you can get the tenant to sign it. It might be easier to do 5 months then a year. Another thing you can do if the lease will be up in December, is to tell them once their lease is up they will be set on a month to month. Most people are hesistant to move out in December, specially if you give them a month to month option.
I don't know about $2900 for the rent. Ask your realtor. He can pull comparable rents for you. I also use the bing search engine. Just type properties for rent in "your city" and it show you rentals from a bunch of different websites. Never try to go to high in rents or else it will sit vacant. Alway rent out at price then slowly increase every year.
I use stessa.com for account (it's awesome, I highly recommend it) and apartments.com to collect rents. I think you can collect rents with stessa as well now. I haven't looked into it because I'm too lazy to switch eveyone over.