I've been to Oktoberfest a couple of times. The second time because others wanted to go. In a way, it's like Neuschwanstein - something to be seen once, then visit better places. My first time to Oktoberfest was after going first to Bonnfest. The locals told me Bonnfest was better (but I couldn't judge until going to both). Bonnfest was a mostly local event, three generations of families sharing beer and song at community tables. It went all night (vs. closing early), people stood on tables/benches (but not in a rowdy way) without getting in trouble, you could order a beer without first finding a seat, and there weren't emergency crews carting people to emergency rooms by the dozens (maybe hundreds?). Oktoberfest is a zoo, a frat party, you should at least try the Stuttgart fest also so you can judge them both yourselves. I'd bet the one you will want to visit again won't be Oktoberfest.
As far as wine is concerned, the Rhine and Mosel river valleys are both famous for their wines - and they have activities around the harvest season. Try the "new wine", it's like drinking fresh grape juice with pulp. It's not exported and doesn't store, so you can only get it there at that time of year. The dry white wines from the region are very good, and not widely available here. I think the Rhine uses brown stemmed glasses and the Mosel green stemmed (or the other way around) so you know exactly what wine you are drinking.
As was said, your first priority is nailing down lodging reservations. Everything fills up. I normally travel happily without reservations. My first time at Oktoberfest, I showed up on opening day sans reservations. It was the only time I seriously thought I'd spend the night on the street. I made some calls to my list with no luck, then tried the TI. It was full of tourists scrambling for lodging - it looked like the floor of the Chicago mercantile. I left and used a pay phone to call every place listed in my guidebook (can't recall if it was Rough Guide or Lonely Planet). Eventually I found a well located and nice pension (at a normal/non-Oktoberfest price).
I also think visiting on a weekday is your better option. A strategy that worked for me was getting an early dinner (don't eat light) from one of the food vendors about 3pm - then head to the tents. It seems to me there is a morning shift (the people who show up first thing) and an evening shift. By late afternoon, the morning shift either leaves for dinner or escorts their friends to the emergency room - either way there seems to be a little lull where you can get a seat (and order a beer) quickly. By nightfall, the tents are full up again and you will wait in a long line for a seat. Last I heard, reservations are only for groups of ten or more.
Regarding tents, they are essentially the same experience - each offering a different beer - some are considered more or less touristy. Read up on the different tents and decide which one you would like most to visit. Get a seat and stay put until you are ready to go home. Tent-hopping will result in spending the night in lines - even on weekdays.