First- welcome to the board! This is one of the most friendly, professional, discussion sites on the net. There are lots of folks here who will provide a lot of excellent insights and advice.
Just a couple of points:
It's already been said, but I think that 30 HP is not nearly enough to drag 36 inch logs. I was dealing with a 10 inch fallen tree a couple of weeks ago and they are very heavy.
Hydro versus gears. I cannot think of one chore that is easier or quicker with a gear tractor. I used a gear tractor for quite a long while and switched to a Kubota L4330 with a hydro tranny and have been very pleased with the simplicity of operation and how fast I can change direction when doing loader work, backing up to hook up an implement, etc. It's worth it to get hydro- even if it means gettting a few more horses to handle it. Unless you are doing row crop work, there is a noticeable improvement in productivity.
Choice and location of dealer: my Kubota dealer is about 10 miles from the wife's horse farm. I blew a hydrolic hose last night and went there this morning to show them the old one and to order a replacement. It's a metal tube with a few unique bends, etc. The replacement part will be air freighted into the dealer tomorrow ($5.00 charge) morning. I will have to go there to pick it up. Point is that if the dealer were 100 miles away, or if you end up with a gray market import, you may not like having your tractor 'down' for several weeks/months while a part is located. This touches on productivity. I only have my days off to do tractor work, and so they are valuable to me. I believe that this is something that Kubota recognizes and they have put this parts network in place. (This is obvioulsy even more important for those that make their living with their equipment).
One of my points is that these were NOT factors that I thought about when I was shopping. I just liked the Kubota Grand L Series and bought one. However, I will tell you that the dealer support and service after the fact is important.
And finally, whichever equipment you bet, please be careful out there. Lots of accidents happen and they can be the worst kind. Tree clearing is dangerous work- so take it easy and be careful.